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 (
    96723, 96725, 96728, 96752, 96767, 97011, 
    97013, 97018, 97021, 97034, 97037, 
    97041, 97044, 97047, 97050, 97052, 
    97053, 97056, 97811, 97812, 97815, 
    97835, 97836, 97839, 97989, 97990, 
    97993, 98031, 98032, 98035, 98158, 
    98160, 98162, 98164, 98166, 98168, 
    98250, 98251, 98252, 98253, 98254, 
    98255, 98256, 98257, 98687, 98689, 
    98698, 98699, 98739, 98741, 98743, 
    98745, 98747, 98749, 99571, 99572, 
    99580, 99582, 99584, 99586, 100067, 
    100069, 100072, 100152, 100153, 100156, 
    100169, 100171, 100173, 100176, 100178, 
    100180, 100321, 100323, 100326, 100605, 
    100606, 100610, 100884, 100887, 100900, 
    100903, 100907, 100910, 100913, 100916, 
    100918, 100919, 100922, 101112, 101115, 
    101121, 101124, 101130, 101133, 101514
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00186

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 (96723,96725,96728,96752,96767,97011,97013,97018,97021,97034,97037,97041,97044,97047,97050,97052,97053,97056,97811,97812,97815,97835,97836,97839,97989,97990,97993,98031,98032,98035,98158,98160,98162,98164,98166,98168,98250,98251,98252,98253,98254,98255,98256,98257,98687,98689,98698,98699,98739,98741,98743,98745,98747,98749,99571,99572,99580,99582,99584,99586,100067,100069,100072,100152,100153,100156,100169,100171,100173,100176,100178,100180,100321,100323,100326,100605,100606,100610,100884,100887,100900,100903,100907,100910,100913,100916,100918,100919,100922,101112,101115,101121,101124,101130,101133,101514)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
96723
96725
96728
96752
96767
97011
97013
97018
97021
97034
97037
97041
97044
97047
97050
97052
97053
97056
97811
97812
97815
97835
97836
97839
97989
97990
97993
98031
98032
98035
98158
98160
98162
98164
98166
98168
98250
98251
98252
98253
98254
98255
98256
98257
98687
98689
98698
98699
98739
98741
98743
98745
98747
98749
99571
99572
99580
99582
99584
99586
100067
100069
100072
100152
100153
100156
100169
100171
100173
100176
100178
100180
100321
100323
100326
100605
100606
100610
100884
100887
100900
100903
100907
100910
100913
100916
100918
100919
100922
101112
101115
101121
101124
101130
101133
101514