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 (
    92196, 92204, 92205, 92206, 92207, 92208, 
    92209, 92442, 92443, 92448, 92001, 
    92147, 92148, 92149, 92349, 92350, 
    92351, 92352, 85647, 85801, 85802, 
    91938, 84700, 86864, 88961, 85800, 
    82352, 91937, 91939, 91940
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00077

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "13.52"
    },
    "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": 30,
      "rows_produced_per_join": 30,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "10.52",
        "eval_cost": "3.00",
        "prefix_cost": "13.52",
        "data_read_per_join": "114K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (92196,92204,92205,92206,92207,92208,92209,92442,92443,92448,92001,92147,92148,92149,92349,92350,92351,92352,85647,85801,85802,91938,84700,86864,88961,85800,82352,91937,91939,91940)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}