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 (
    87026, 87051, 87086, 87109, 83576, 83578, 
    90583, 90584, 90915, 90917, 90994, 
    90996, 91396, 91398, 91400, 91402, 
    91404, 91406, 91408, 91410, 91412, 
    91414, 91416, 91418, 91009, 91021, 
    91033, 91046, 89495, 89496, 89503, 
    89504, 89511, 89512, 89519, 89520, 
    86903, 86928, 86964, 86989, 87025, 
    87050, 87108, 90796, 83289, 83291, 
    83296, 83298
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00097

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 (87026,87051,87086,87109,83576,83578,90583,90584,90915,90917,90994,90996,91396,91398,91400,91402,91404,91406,91408,91410,91412,91414,91416,91418,91009,91021,91033,91046,89495,89496,89503,89504,89511,89512,89519,89520,86903,86928,86964,86989,87025,87050,87108,90796,83289,83291,83296,83298)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}