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 (
    99342, 99343, 99404, 99405, 99406, 99407, 
    99408, 99409, 99410, 99411, 99422, 
    99423, 99424, 99425, 99426, 99427, 
    99428, 99429, 99430, 99431, 99432, 
    99433, 99434, 99435, 99436, 99437, 
    99491, 99492, 99493, 99494, 99495, 
    99496, 99497, 99498, 99499, 99500, 
    99501, 99502, 99503, 99504, 99505, 
    99506, 99508, 99509, 99510, 99512, 
    99513, 99514, 99516, 99517, 99518, 
    99519, 99520, 99521, 99522, 99523, 
    99524, 99525, 99526, 99527, 99529, 
    99530, 99531, 99532, 99533, 99534, 
    99535, 99536, 99537, 99538, 99539, 
    99540, 99541, 99542, 99543, 99544, 
    99545, 99546, 99547, 99548, 99549, 
    99550, 99551, 99552, 99553, 99554, 
    99555, 99556, 99557, 99574, 99575, 
    99576, 100143, 100161, 100162, 100163
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00177

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "51.87"
    },
    "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": 96,
      "rows_produced_per_join": 96,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "42.27",
        "eval_cost": "9.60",
        "prefix_cost": "51.87",
        "data_read_per_join": "366K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (99342,99343,99404,99405,99406,99407,99408,99409,99410,99411,99422,99423,99424,99425,99426,99427,99428,99429,99430,99431,99432,99433,99434,99435,99436,99437,99491,99492,99493,99494,99495,99496,99497,99498,99499,99500,99501,99502,99503,99504,99505,99506,99508,99509,99510,99512,99513,99514,99516,99517,99518,99519,99520,99521,99522,99523,99524,99525,99526,99527,99529,99530,99531,99532,99533,99534,99535,99536,99537,99538,99539,99540,99541,99542,99543,99544,99545,99546,99547,99548,99549,99550,99551,99552,99553,99554,99555,99556,99557,99574,99575,99576,100143,100161,100162,100163)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
99342
99343
99404
99405
99406
99407
99408
99409
99410
99411
99422
99423
99424
99425
99426
99427
99428
99429
99430
99431
99432
99433
99434
99435
99436
99437
99491
99492
99493
99494
99495
99496
99497
99498
99499
99500
99501
99502
99503
99504
99505
99506
99508
99509
99510
99512
99513
99514
99516
99517
99518
99519
99520
99521
99522
99523
99524
99525
99526
99527
99529
99530
99531
99532
99533
99534
99535
99536
99537
99538
99539
99540
99541
99542
99543
99544
99545
99546
99547
99548
99549
99550
99551
99552
99553
99554
99555
99556
99557
99574
99575
99576
100143
100161
100162
100163