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 (
    95574, 95575, 95578, 95579, 95580, 95581, 
    95587, 95588, 95589, 95590, 95591, 
    95629, 95630, 95631, 95632, 95633, 
    95634, 95635, 95636, 95637, 95641, 
    95642, 95643, 95644, 95647, 95648, 
    95649, 95650, 95651, 95652, 95935, 
    95938, 95939, 95942, 95943, 96341, 
    96342, 96343, 96344, 96345, 96346, 
    96347, 96348, 96602, 96603, 96606, 
    96608, 96610
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00096

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 (95574,95575,95578,95579,95580,95581,95587,95588,95589,95590,95591,95629,95630,95631,95632,95633,95634,95635,95636,95637,95641,95642,95643,95644,95647,95648,95649,95650,95651,95652,95935,95938,95939,95942,95943,96341,96342,96343,96344,96345,96346,96347,96348,96602,96603,96606,96608,96610)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
95574
95575
95578
95579
95580
95581
95587
95588
95589
95590
95591
95629
95630
95631
95632
95633
95634
95635
95636
95637
95641
95642
95643
95644
95647
95648
95649
95650
95651
95652
95935
95938
95939
95942
95943
96341
96342
96343
96344
96345
96346
96347
96348
96602
96603
96606
96608
96610