SELECT 
  SQL_CALC_FOUND_ROWS products.product_id, 
  (
    CASE WHEN descr1.cp_st_h1 <> '' THEN descr1.cp_st_h1 ELSE descr1.product END
  ) AS product, 
  companies.company as company_name, 
  descr1.cp_hash_template_as_timestamp_value, 
  products.product_type, 
  products.parent_product_id, 
  1 as instock_marker, 
  IF(
    products.product_type = 'V', 
    IF (
      mccd__variation_stocks.parent_product_id IS NULL, 
      0, 1
    ), 
    IF(
      products.amount > 0, 
      1, 
      IF(products.tracking = 'D', 1, 0)
    )
  ) as instock_sorting, 
  CASE WHEN csc_product_currency_items.currency IS NULL THEN "D" ELSE csc_product_currency_items.currency END as currency, 
  products.amount, 
  products.purchase_qty, 
  products.is_invoice, 
  products.ei_order_id, 
  products.ei_status, 
  products.ei_for_user_id 
FROM 
  cscart_products as products 
  LEFT JOIN cscart_product_features_values as var_val_2 ON var_val_2.product_id = products.product_id 
  AND var_val_2.lang_code = 'en' 
  AND var_val_2.feature_id = 2 
  LEFT JOIN cscart_mb_vehicle_listing_index AS mb_vehicle_listing_index ON mb_vehicle_listing_index.product_id = products.product_id 
  LEFT JOIN cscart_mb_salvage_cases AS mb_recaon_visibility_case ON mb_recaon_visibility_case.case_id = mb_vehicle_listing_index.case_id 
  LEFT JOIN cscart_product_descriptions as descr1 ON descr1.product_id = products.product_id 
  AND descr1.lang_code = 'en' 
  LEFT JOIN cscart_product_prices as prices ON prices.product_id = products.product_id 
  AND prices.lower_limit = 1 
  LEFT JOIN cscart_companies AS companies ON companies.company_id = products.company_id 
  INNER JOIN cscart_products_categories as products_categories ON products_categories.product_id = products.product_id 
  INNER JOIN cscart_categories ON cscart_categories.category_id = products_categories.category_id 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  AND cscart_categories.storefront_id IN (0, 1) 
  LEFT JOIN (
    SELECT 
      parent_product_id 
    FROM 
      cscart_products 
    WHERE 
      parent_product_id != 0 
      AND amount > 0 
      AND product_type = 'V' 
    GROUP BY 
      parent_product_id
  ) AS mccd__variation_stocks ON mccd__variation_stocks.parent_product_id = products.parent_product_id 
  LEFT JOIN cscart_csc_product_currency_items as csc_product_currency_items ON csc_product_currency_items.product_id = products.product_id 
  AND csc_product_currency_items.company_id = 0 
WHERE 
  1 
  AND (
    var_val_2.variant_id IN (12)
  ) 
  AND (
    mb_recaon_visibility_case.case_id IS NULL 
    OR mb_recaon_visibility_case.import_source NOT LIKE 'recaon_%' 
    OR mb_vehicle_listing_index.storefront_id = 1
  ) 
  AND (
    mb_recaon_visibility_case.case_id IS NULL 
    OR mb_recaon_visibility_case.selected_flow != 'direct_sale' 
    OR mb_recaon_visibility_case.sale_listing_status != 'hold'
  ) 
  AND cscart_categories.category_id IN (
    499, 528, 503, 530, 533, 546, 548, 515, 
    514, 525, 537, 524, 534, 550, 516, 527, 
    545, 551, 517, 523, 538, 544, 553, 539, 
    547, 554, 540, 518, 531, 541, 519, 526, 
    542, 552, 562, 543, 549, 521, 535, 522, 
    532, 536, 529, 558, 559, 560, 561, 572, 
    573, 574, 575, 576, 577, 578, 579, 580, 
    581, 582, 583, 584, 585, 586, 587, 588, 
    589, 590, 591, 592, 593, 594, 595, 596, 
    597, 598, 599, 600, 601, 602, 603, 604, 
    606, 607, 630, 631, 632, 633, 634, 635, 
    637
  ) 
  AND companies.status IN ('A', 'S') 
  AND products.company_id IN (1, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 0) 
  AND (
    products.usergroup_ids = '' 
    OR FIND_IN_SET(0, products.usergroup_ids) 
    OR FIND_IN_SET(1, products.usergroup_ids)
  ) 
  AND products.status IN ('A') 
  AND prices.usergroup_id IN (0, 0, 1) 
  AND products.parent_product_id = 0 
  AND products.is_invoice = 'N' 
  AND products.product_type != 'D' 
GROUP BY 
  products.product_id 
ORDER BY 
  instock_sorting DESC, 
  products.timestamp desc, 
  products.product_id ASC 
LIMIT 
  6640, 16

Query time 0.75715

JSON explain

{
  "query_block": {
    "select_id": 1,
    "filesort": {
      "sort_key": "if(products.product_type = 'V',if(mccd__variation_stocks.parent_product_id is null,0,1),if(products.amount > 0,1,if(products.tracking = 'D',1,0))) desc, products.`timestamp` desc, products.product_id",
      "temporary_table": {
        "table": {
          "table_name": "companies",
          "access_type": "ALL",
          "possible_keys": ["PRIMARY"],
          "rows": 11,
          "filtered": 100,
          "attached_condition": "companies.`status` in ('A','S')"
        },
        "table": {
          "table_name": "products",
          "access_type": "ref",
          "possible_keys": [
            "PRIMARY",
            "status",
            "idx_parent_product_id",
            "idx_company_id"
          ],
          "key": "idx_company_id",
          "key_length": "4",
          "used_key_parts": ["company_id"],
          "ref": ["devmotorsbay.companies.company_id"],
          "rows": 1190,
          "filtered": 98.1960144,
          "index_condition": "products.company_id in (1,3,5,6,7,8,10,11,12,13,15,0)",
          "attached_condition": "products.parent_product_id = 0 and (products.usergroup_ids = '' or find_in_set(0,products.usergroup_ids) or find_in_set(1,products.usergroup_ids)) and products.`status` = 'A' and products.is_invoice = 'N' and products.product_type <> 'D'"
        },
        "table": {
          "table_name": "mb_vehicle_listing_index",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "4",
          "used_key_parts": ["product_id"],
          "ref": ["devmotorsbay.products.product_id"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "trigcond(mb_vehicle_listing_index.product_id = products.product_id)"
        },
        "table": {
          "table_name": "mb_recaon_visibility_case",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "4",
          "used_key_parts": ["case_id"],
          "ref": ["devmotorsbay.mb_vehicle_listing_index.case_id"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "trigcond((mb_recaon_visibility_case.case_id is null or mb_recaon_visibility_case.import_source  not like 'recaon_%' or mb_vehicle_listing_index.storefront_id = 1) and (mb_recaon_visibility_case.case_id is null or mb_recaon_visibility_case.selected_flow <> 'direct_sale' or mb_recaon_visibility_case.sale_listing_status <> 'hold')) and trigcond(trigcond(mb_vehicle_listing_index.case_id is not null))"
        },
        "table": {
          "table_name": "var_val_2",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY",
            "fl",
            "variant_id",
            "lang_code",
            "product_id",
            "fpl",
            "idx_product_feature_variant_id"
          ],
          "key": "PRIMARY",
          "key_length": "15",
          "used_key_parts": ["feature_id", "product_id", "variant_id", "lang_code"],
          "ref": ["const", "devmotorsbay.products.product_id", "const", "const"],
          "rows": 1,
          "filtered": 5.998818398,
          "attached_condition": "var_val_2.lang_code = 'en'",
          "using_index": true
        },
        "table": {
          "table_name": "prices",
          "access_type": "ref",
          "possible_keys": [
            "usergroup",
            "product_id",
            "lower_limit",
            "usergroup_id"
          ],
          "key": "usergroup",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "ref": ["devmotorsbay.products.product_id"],
          "rows": 1,
          "filtered": 99.99243927,
          "attached_condition": "prices.lower_limit = 1 and prices.usergroup_id in (0,0,1)",
          "using_index": true
        },
        "table": {
          "table_name": "products_categories",
          "access_type": "ref",
          "possible_keys": ["PRIMARY", "pt"],
          "key": "pt",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "ref": ["devmotorsbay.products.product_id"],
          "rows": 1,
          "filtered": 100
        },
        "table": {
          "table_name": "cscart_categories",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY", "c_status", "p_category_id"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["category_id"],
          "ref": ["devmotorsbay.products_categories.category_id"],
          "rows": 1,
          "filtered": 100,
          "index_condition": "cscart_categories.category_id in (499,528,503,530,533,546,548,515,514,525,537,524,534,550,516,527,545,551,517,523,538,544,553,539,547,554,540,518,531,541,519,526,542,552,562,543,549,521,535,522,532,536,529,558,559,560,561,572,573,574,575,576,577,578,579,580,581,582,583,584,585,586,587,588,589,590,591,592,593,594,595,596,597,598,599,600,601,602,603,604,606,607,630,631,632,633,634,635,637)",
          "attached_condition": "(cscart_categories.usergroup_ids = '' or find_in_set(0,cscart_categories.usergroup_ids) or find_in_set(1,cscart_categories.usergroup_ids)) and cscart_categories.`status` in ('A','H') and cscart_categories.storefront_id in (0,1)"
        },
        "table": {
          "table_name": "descr1",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY", "product_id", "idx_product_lang"],
          "key": "PRIMARY",
          "key_length": "9",
          "used_key_parts": ["product_id", "lang_code"],
          "ref": ["devmotorsbay.products.product_id", "const"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "trigcond(descr1.lang_code = 'en')"
        },
        "block-nl-join": {
          "table": {
            "table_name": "<derived2>",
            "access_type": "ALL",
            "rows": 25,
            "filtered": 100,
            "attached_condition": "mccd__variation_stocks.parent_product_id = 0"
          },
          "buffer_type": "flat",
          "buffer_size": "2048Kb",
          "join_type": "BNL",
          "attached_condition": "trigcond(mccd__variation_stocks.parent_product_id = 0)",
          "materialized": {
            "query_block": {
              "select_id": 2,
              "table": {
                "table_name": "cscart_products",
                "access_type": "range",
                "possible_keys": ["idx_parent_product_id"],
                "key": "idx_parent_product_id",
                "key_length": "4",
                "used_key_parts": ["parent_product_id"],
                "rows": 26,
                "filtered": 100,
                "index_condition": "cscart_products.parent_product_id <> 0",
                "attached_condition": "cscart_products.amount > 0 and cscart_products.product_type = 'V'"
              }
            }
          }
        },
        "table": {
          "table_name": "csc_product_currency_items",
          "access_type": "eq_ref",
          "possible_keys": ["product_id_company_id"],
          "key": "product_id_company_id",
          "key_length": "16",
          "used_key_parts": ["product_id", "company_id"],
          "ref": ["devmotorsbay.products.product_id", "const"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "trigcond(csc_product_currency_items.product_id = products.product_id)"
        }
      }
    }
  }
}