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 (
    99807, 99808, 99809, 99810, 99811, 99812, 
    99813, 99814, 99815, 99816, 99817, 
    99818, 99819, 99820, 99821, 99822, 
    99823, 99824, 99825, 99826, 99827, 
    99828, 99829, 99830, 99831, 99835, 
    99836, 99837, 99838, 99885, 99886, 
    99887, 99888, 99889, 99890, 99891, 
    99892, 99919, 99920, 99921, 99922, 
    99923, 99924, 99925, 99926, 99927, 
    99928, 99929
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00087

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 (99807,99808,99809,99810,99811,99812,99813,99814,99815,99816,99817,99818,99819,99820,99821,99822,99823,99824,99825,99826,99827,99828,99829,99830,99831,99835,99836,99837,99838,99885,99886,99887,99888,99889,99890,99891,99892,99919,99920,99921,99922,99923,99924,99925,99926,99927,99928,99929)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}