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 (
    96259, 96260, 96261, 96262, 96263, 96264, 
    96265, 96266, 96267, 96268, 96269, 
    96270, 96271, 96272, 96273, 96274, 
    96275, 96276, 96277, 96278, 96279, 
    96280, 96281, 96282, 96283, 96284, 
    96285, 96286, 96287, 96288, 96289, 
    96290, 96291, 96292, 96293, 96294, 
    96522, 96523, 96524, 96525, 96526, 
    96527, 96528, 96574, 96575, 96576, 
    96577, 96578
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00097

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 (96259,96260,96261,96262,96263,96264,96265,96266,96267,96268,96269,96270,96271,96272,96273,96274,96275,96276,96277,96278,96279,96280,96281,96282,96283,96284,96285,96286,96287,96288,96289,96290,96291,96292,96293,96294,96522,96523,96524,96525,96526,96527,96528,96574,96575,96576,96577,96578)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
96259
96260
96261
96262
96263
96264
96265
96266
96267
96268
96269
96270
96271
96272
96273
96274
96275
96276
96277
96278
96279
96280
96281
96282
96283
96284
96285
96286
96287
96288
96289
96290
96291
96292
96293
96294
96522
96523
96524
96525
96526
96527
96528
96574
96575
96576
96577
96578