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 (
    101017, 101018, 101019, 101020, 101021, 
    101625, 101637, 101638, 101669, 101670, 
    101672, 101673, 101674, 101675, 101676, 
    101677, 101682, 101683, 101688, 101689, 
    101690, 101691, 101692, 101693, 101696, 
    101697, 101698, 101699, 101700, 101701, 
    101702, 101703, 101704, 101705, 101706, 
    101707, 101708, 101709, 101710, 101711, 
    101712, 101713, 101714, 101715, 101716, 
    101717, 101718, 101719
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00096

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "25.94"
    },
    "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": "21.14",
        "eval_cost": "4.80",
        "prefix_cost": "25.94",
        "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 (101017,101018,101019,101020,101021,101625,101637,101638,101669,101670,101672,101673,101674,101675,101676,101677,101682,101683,101688,101689,101690,101691,101692,101693,101696,101697,101698,101699,101700,101701,101702,101703,101704,101705,101706,101707,101708,101709,101710,101711,101712,101713,101714,101715,101716,101717,101718,101719)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}