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 (
    99396, 99397, 99398, 100358, 101872, 
    101873, 101874, 101875, 101876, 101877, 
    101878, 101879, 101880, 101881, 101882, 
    101883, 101884, 101885, 101886, 101887, 
    101888, 101889, 101890, 101891, 101892, 
    101893, 101894, 101895, 101896, 101897, 
    101898, 101899, 101900, 101901, 101902, 
    101903, 101904, 101905, 101906, 101907, 
    101908, 101909, 101910, 101911, 101912, 
    101913, 101914, 101915, 101916, 101917, 
    101918, 101919, 101920, 101921, 101922, 
    101923, 101924, 101925, 101926, 101927, 
    101932, 101933, 101934, 101935, 101936, 
    101937, 101938, 101939, 101940, 101941, 
    101942, 101943, 101944, 101945, 101946, 
    101947, 101948, 101949, 101950, 101951
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00173

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "36.04"
    },
    "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": 80,
      "rows_produced_per_join": 80,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "28.04",
        "eval_cost": "8.00",
        "prefix_cost": "36.04",
        "data_read_per_join": "305K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (99396,99397,99398,100358,101872,101873,101874,101875,101876,101877,101878,101879,101880,101881,101882,101883,101884,101885,101886,101887,101888,101889,101890,101891,101892,101893,101894,101895,101896,101897,101898,101899,101900,101901,101902,101903,101904,101905,101906,101907,101908,101909,101910,101911,101912,101913,101914,101915,101916,101917,101918,101919,101920,101921,101922,101923,101924,101925,101926,101927,101932,101933,101934,101935,101936,101937,101938,101939,101940,101941,101942,101943,101944,101945,101946,101947,101948,101949,101950,101951)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
99396
99397
99398
100358
101872
101873
101874
101875
101876
101877
101878
101879
101880
101881
101882
101883
101884
101885
101886
101887
101888
101889
101890
101891
101892
101893
101894
101895
101896
101897
101898
101899
101900
101901
101902
101903
101904
101905
101906
101907
101908
101909
101910
101911
101912
101913
101914
101915
101916
101917
101918
101919
101920
101921
101922
101923
101924
101925
101926
101927
101932
101933
101934
101935
101936
101937
101938
101939
101940
101941
101942
101943
101944
101945
101946
101947
101948
101949
101950
101951