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 (
    97688, 97689, 97690, 97691, 97692, 97693, 
    97694, 97695, 97696, 97707, 97708, 
    97709, 97710, 97711, 97712, 97728, 
    97729, 97730, 97731, 97732, 97733, 
    97734, 97735, 97736, 97737, 97738, 
    97739, 97740, 97741, 97742, 97743, 
    97744, 97745, 97746, 97747, 97748, 
    97749, 97750, 97751, 97752, 97753, 
    97754, 97755, 97756, 97757, 97758, 
    97759, 97760
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00095

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "26.88"
    },
    "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": "22.08",
        "eval_cost": "4.80",
        "prefix_cost": "26.88",
        "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 (97688,97689,97690,97691,97692,97693,97694,97695,97696,97707,97708,97709,97710,97711,97712,97728,97729,97730,97731,97732,97733,97734,97735,97736,97737,97738,97739,97740,97741,97742,97743,97744,97745,97746,97747,97748,97749,97750,97751,97752,97753,97754,97755,97756,97757,97758,97759,97760)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}