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 (
    262860, 262924, 262345, 359697, 262231, 
    359715, 264355, 262341, 359780, 359723, 
    265053, 265021, 265024, 359705, 262230, 
    262232, 388351, 359792, 265023, 263008, 
    265052, 263011, 359800, 263010, 262838, 
    262234, 262966, 265043, 359796, 265226, 
    359784, 265229, 359802, 265228, 265045, 
    270360, 359788, 265046, 265030, 265047, 
    265227, 265225, 265064, 265044, 273206, 
    265224, 273057, 270409, 273061, 270364, 
    273066, 265369, 273062, 273060, 273064, 
    265371, 265370, 273063, 273058, 265372, 
    273065, 435334, 435333, 273059, 435332, 
    273207, 270410
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00180

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "93.92"
    },
    "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": 67,
      "rows_produced_per_join": 67,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "80.52",
        "eval_cost": "13.40",
        "prefix_cost": "93.92",
        "data_read_per_join": "457K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`webmarco`.`cscart_product_descriptions`.`product_id` in (262860,262924,262345,359697,262231,359715,264355,262341,359780,359723,265053,265021,265024,359705,262230,262232,388351,359792,265023,263008,265052,263011,359800,263010,262838,262234,262966,265043,359796,265226,359784,265229,359802,265228,265045,270360,359788,265046,265030,265047,265227,265225,265064,265044,273206,265224,273057,270409,273061,270364,273066,265369,273062,273060,273064,265371,265370,273063,273058,265372,273065,435334,435333,273059,435332,273207,270410)) and (`webmarco`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}