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 (
    94091, 94092, 94094, 94100, 94101, 94102, 
    94103, 94104, 94105, 94106, 94107, 
    94108, 94109, 94110, 94111, 94112, 
    94113, 94114, 94115, 94838, 94849, 
    94965, 94966, 94967, 94968, 94969, 
    94970, 94971, 94972, 94973, 94974, 
    94975, 94976, 94977, 94978, 94979, 
    94980, 94981, 94982, 94983, 94984, 
    94985, 94986, 94987, 94988, 94989, 
    94990, 94991
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00093

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.62"
    },
    "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": "16.82",
        "eval_cost": "4.80",
        "prefix_cost": "21.62",
        "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 (94091,94092,94094,94100,94101,94102,94103,94104,94105,94106,94107,94108,94109,94110,94111,94112,94113,94114,94115,94838,94849,94965,94966,94967,94968,94969,94970,94971,94972,94973,94974,94975,94976,94977,94978,94979,94980,94981,94982,94983,94984,94985,94986,94987,94988,94989,94990,94991)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}