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 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    84715, 92161, 92162, 92163, 92164, 92165, 
    92166, 84714, 84713, 84712, 84711, 
    84710, 87918, 87919, 87920, 87924, 
    87926, 87930, 87931, 87932, 84940, 
    84941, 87898, 87899, 87902, 84728, 
    84729, 84730, 84731, 84732, 84733, 
    87921, 87923, 87933, 87935, 84720, 
    84723, 84727, 84939, 84734, 84735, 
    84938, 84719, 84722, 84724, 84744, 
    84718, 84721
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00095

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.63"
    },
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "lang_code"
      ],
      "key_length": "9",
      "rows_examined_per_scan": 48,
      "rows_produced_per_join": 48,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "16.83",
        "eval_cost": "4.80",
        "prefix_cost": "21.63",
        "data_read_per_join": "183K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (84715,92161,92162,92163,92164,92165,92166,84714,84713,84712,84711,84710,87918,87919,87920,87924,87926,87930,87931,87932,84940,84941,87898,87899,87902,84728,84729,84730,84731,84732,84733,87921,87923,87933,87935,84720,84723,84727,84939,84734,84735,84938,84719,84722,84724,84744,84718,84721)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}