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 (
    97761, 97762, 97763, 97764, 97778, 97779, 
    97780, 97781, 97782, 97790, 97791, 
    97792, 97793, 97794, 97795, 97796, 
    97797, 97798, 97818, 97819, 97820, 
    97821, 97822, 97823, 97824, 97825, 
    97826, 97831, 97832, 97874, 97875, 
    97876, 97877, 97878, 97879, 97880, 
    97881, 97882, 97883, 97884, 97885, 
    97886, 97887, 97888, 97889, 97959, 
    98001, 98002
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00095

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 (97761,97762,97763,97764,97778,97779,97780,97781,97782,97790,97791,97792,97793,97794,97795,97796,97797,97798,97818,97819,97820,97821,97822,97823,97824,97825,97826,97831,97832,97874,97875,97876,97877,97878,97879,97880,97881,97882,97883,97884,97885,97886,97887,97888,97889,97959,98001,98002)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}