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 (
    94405, 94406, 94407, 94408, 94409, 94410, 
    94411, 94412, 94413, 94414, 94415, 
    94416, 94417, 94418, 94420, 94421, 
    94422, 94425, 94854, 94855, 94856, 
    94857, 94861, 94862, 94863, 94864, 
    94865, 94866, 94869, 94872, 94873, 
    94874, 94875, 94876, 94877, 94878, 
    94879, 94880, 94881, 94882, 94883, 
    94884, 94885, 94886, 94887, 94888, 
    94889, 94890
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00110

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 (94405,94406,94407,94408,94409,94410,94411,94412,94413,94414,94415,94416,94417,94418,94420,94421,94422,94425,94854,94855,94856,94857,94861,94862,94863,94864,94865,94866,94869,94872,94873,94874,94875,94876,94877,94878,94879,94880,94881,94882,94883,94884,94885,94886,94887,94888,94889,94890)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
94405
94406
94407
94408
94409
94410
94411
94412
94413
94414
94415
94416
94417
94418
94420
94421
94422
94425
94854
94855
94856
94857
94861
94862
94863
94864
94865
94866
94869
94872
94873
94874
94875
94876
94877
94878
94879
94880
94881
94882
94883
94884
94885
94886
94887
94888
94889
94890