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 (
    89307, 82362, 89319, 89326, 91960, 90096, 
    89312, 90118, 89345, 89193, 89318, 
    89347, 89346, 89197, 89255, 89348, 
    89261, 89314, 89320, 83140, 84119, 
    89260, 89315, 89256, 82360, 89313, 
    89316, 91953, 91954, 91955, 91956, 
    91957, 91958, 91959, 84290, 82404, 
    83118, 84115, 89310, 82342, 89311, 
    82367, 89304, 86236, 86815, 89973, 
    82364, 82363
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00098

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 (89307,82362,89319,89326,91960,90096,89312,90118,89345,89193,89318,89347,89346,89197,89255,89348,89261,89314,89320,83140,84119,89260,89315,89256,82360,89313,89316,91953,91954,91955,91956,91957,91958,91959,84290,82404,83118,84115,89310,82342,89311,82367,89304,86236,86815,89973,82364,82363)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}