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 (
    96402, 96403, 96404, 96405, 96406, 96407, 
    96408, 96409, 96410, 96411, 96412, 
    96413, 96414, 96415, 96416, 96417, 
    96418, 96419, 96420, 96421, 96422, 
    96423, 96424, 96425, 96426, 96427, 
    96428, 96429, 96430, 96431, 96432, 
    96433, 96434, 96435, 96436, 96437, 
    96438, 96439, 96440, 96441, 96442, 
    96443, 96444, 96445, 96446, 96447, 
    96448, 96449, 96450, 96451, 96452, 
    96453, 96454, 96455, 96456, 96457, 
    96458, 96459, 96460, 96461, 96462, 
    96463, 96464, 96465, 96466, 96467, 
    96468, 96469, 96470, 96471, 96472, 
    96473, 96474, 96475, 96476, 96477, 
    96478, 96479, 96480, 96481, 96482, 
    96483, 96484, 96485, 96486, 96487, 
    96488, 96489, 97802, 97803, 97804, 
    97805, 97806, 97807, 97808, 97809
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00283

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "43.24"
    },
    "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": "33.64",
        "eval_cost": "9.60",
        "prefix_cost": "43.24",
        "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 (96402,96403,96404,96405,96406,96407,96408,96409,96410,96411,96412,96413,96414,96415,96416,96417,96418,96419,96420,96421,96422,96423,96424,96425,96426,96427,96428,96429,96430,96431,96432,96433,96434,96435,96436,96437,96438,96439,96440,96441,96442,96443,96444,96445,96446,96447,96448,96449,96450,96451,96452,96453,96454,96455,96456,96457,96458,96459,96460,96461,96462,96463,96464,96465,96466,96467,96468,96469,96470,96471,96472,96473,96474,96475,96476,96477,96478,96479,96480,96481,96482,96483,96484,96485,96486,96487,96488,96489,97802,97803,97804,97805,97806,97807,97808,97809)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
96402
96403
96404
96405
96406
96407
96408
96409
96410
96411
96412
96413
96414
96415
96416
96417
96418
96419
96420
96421
96422
96423
96424
96425
96426
96427
96428
96429
96430
96431
96432
96433
96434
96435
96436
96437
96438
96439
96440
96441
96442
96443
96444
96445
96446
96447
96448
96449
96450
96451
96452
96453
96454
96455
96456
96457
96458
96459
96460
96461
96462
96463
96464
96465
96466
96467
96468
96469
96470
96471
96472
96473
96474
96475
96476
96477
96478
96479
96480
96481
96482
96483
96484
96485
96486
96487
96488
96489
97802
97803
97804
97805
97806
97807
97808
97809