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 (
    19348, 19349, 19350, 19351, 19352, 19353, 
    19354, 19355, 19356, 19357, 19358, 
    19359, 19360, 19361, 19362, 19363, 
    19364, 19365, 19366, 19367, 19368, 
    19369, 19370, 19371
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "18.59"
    },
    "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": 24,
      "rows_produced_per_join": 24,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "16.19",
        "eval_cost": "2.40",
        "prefix_cost": "18.59",
        "data_read_per_join": "109K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`cscart_db`.`cscart_product_descriptions`.`product_id` in (19348,19349,19350,19351,19352,19353,19354,19355,19356,19357,19358,19359,19360,19361,19362,19363,19364,19365,19366,19367,19368,19369,19370,19371)) and (`cscart_db`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}