SELECT 
  cscart_seo_names.object_id AS product_id, 
  cscart_seo_names.name AS seo_name, 
  cscart_seo_names.path AS seo_path 
FROM 
  cscart_seo_names 
WHERE 
  cscart_seo_names.object_id IN (
    20989, 20990, 20991, 20992, 20993, 20994, 
    20995, 20996, 20997, 20998, 20999, 
    21000, 21001, 21002, 21003, 21004
  ) 
  AND cscart_seo_names.type = "p" 
  AND cscart_seo_names.dispatch = "" 
  AND cscart_seo_names.lang_code = 'ru'

Query time 0.00055

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_seo_names",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "dispatch"],
      "key": "PRIMARY",
      "key_length": "206",
      "used_key_parts": ["object_id", "type", "dispatch", "lang_code"],
      "rows": 16,
      "filtered": 100,
      "index_condition": "cscart_seo_names.object_id in (20989,20990,20991,20992,20993,20994,20995,20996,20997,20998,20999,21000,21001,21002,21003,21004) and cscart_seo_names.`type` = 'p' and cscart_seo_names.dispatch = '' and cscart_seo_names.lang_code = 'ru'"
    }
  }
}