SELECT 
  cscart_ult_product_descriptions.product_id, 
  cscart_ult_product_descriptions.short_description, 
  IF(
    cscart_ult_product_descriptions.short_description = "", 
    cscart_ult_product_descriptions.full_description, 
    ""
  ) AS full_description, 
  cscart_ult_product_descriptions.meta_keywords, 
  cscart_ult_product_descriptions.meta_description, 
  cscart_ult_product_descriptions.search_words, 
  cscart_ult_product_descriptions.promo_text 
FROM 
  cscart_ult_product_descriptions 
WHERE 
  cscart_ult_product_descriptions.product_id IN (
    1666, 1665, 1663, 1660, 1662, 255, 1661, 
    1658, 1657, 1656, 1655, 1654, 1653, 
    1652, 1651, 1650, 1324, 1647, 1646, 
    1645, 1643, 1642, 1641, 1640
  ) 
  AND cscart_ult_product_descriptions.company_id = 1 
  AND cscart_ult_product_descriptions.lang_code = 'en'

Query time 0.00110

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_ult_product_descriptions",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "product_id", "company_id"],
      "key": "PRIMARY",
      "key_length": "13",
      "used_key_parts": ["product_id", "lang_code", "company_id"],
      "rows": 24,
      "filtered": 100,
      "index_condition": "cscart_ult_product_descriptions.company_id = 1 and cscart_ult_product_descriptions.product_id in (1666,1665,1663,1660,1662,255,1661,1658,1657,1656,1655,1654,1653,1652,1651,1650,1324,1647,1646,1645,1643,1642,1641,1640) and cscart_ult_product_descriptions.lang_code = 'en'"
    }
  }
}

Result

product_id short_description full_description meta_keywords meta_description search_words promo_text
255
1324
1640
1641
1642
1643
1645
1646
1647
1650
1651
1652
1653
1654
1655
1656
1657
1658
1660
1661
1662
1663
1665
1666