SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  IF(
    cscart_product_descriptions.short_description = '' 
    OR cscart_product_descriptions.short_description IS NULL, 
    cscart_product_descriptions.full_description, 
    ''
  ) AS full_description, 
  cscart_product_descriptions.unit_name 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    23695, 23696, 23697, 23698, 23699, 23700, 
    23701, 23702, 23703, 23704, 23705, 
    23706, 23707, 23708, 23709, 23710
  ) 
  AND cscart_product_descriptions.lang_code = 'ru'

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "product_id", "idx_product_lang"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["product_id", "lang_code"],
      "rows": 16,
      "filtered": 100,
      "index_condition": "cscart_product_descriptions.product_id in (23695,23696,23697,23698,23699,23700,23701,23702,23703,23704,23705,23706,23707,23708,23709,23710) and cscart_product_descriptions.lang_code = 'ru'"
    }
  }
}

Result

product_id short_description full_description unit_name
23695 Seal-duct NO.1<p>Part number 97245AR000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
23696 Seal-duct NO.2<p>Part number 97245AR500</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
23697 Seal-duct NO.3<p>Part number 97245AR600</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
23698 Seal-duct NO.4<p>Part number 97245AR700</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
23699 Seal-duct<p>Part number 97245AR800</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
23700 Actuator-Mode<p>Part number 97159AR000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
23701 Actuator-Mode<p>Part number 97159AR050</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
23702 Seal-Foot<p>Part number 971A3AR020</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
23703 Duct - shower, right<p>Part number 97282AR000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
23704 Duct - shower, left<p>Part number 97279AR000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
23705 seal<p>Part number 971A3AR000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
23706 Evaporator Assembly<p>Part number 97139AR000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
23707 Duct - shower foot, left<p>Part number 97279AR050</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
23708 hose-drain<p>Part number 97173AR000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
23709 Duct Assembly - Air Intake<p>Part number 97190AR000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
23710 Case-left<p>Part number 971A7AR000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>