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 (
    93833, 93834, 93835, 93836, 93837, 93838, 
    93839, 93840, 93841, 93882, 93883, 
    93884, 93885, 94367, 94368, 94369, 
    94370, 94371, 94372, 94373, 94374, 
    94375, 94376, 94377, 94378, 94379, 
    94380, 94438, 94463, 94464
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "13.52"
    },
    "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": 30,
      "rows_produced_per_join": 30,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "10.52",
        "eval_cost": "3.00",
        "prefix_cost": "13.52",
        "data_read_per_join": "114K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (93833,93834,93835,93836,93837,93838,93839,93840,93841,93882,93883,93884,93885,94367,94368,94369,94370,94371,94372,94373,94374,94375,94376,94377,94378,94379,94380,94438,94463,94464)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
93833
93834
93835
93836
93837
93838
93839
93840
93841
93882
93883
93884
93885
94367
94368
94369
94370
94371
94372
94373
94374
94375
94376
94377
94378
94379
94380
94438
94463
94464