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 (
    93346, 93347, 93348, 93349, 93350, 93351, 
    93352, 93353, 93354, 93355, 93750, 
    93751, 93752, 93792, 93793, 93794, 
    93848, 93849, 93886, 93887, 93888, 
    93889, 93890, 93891, 93892, 93893, 
    94119, 94120, 94121, 94122
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00074

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 (93346,93347,93348,93349,93350,93351,93352,93353,93354,93355,93750,93751,93752,93792,93793,93794,93848,93849,93886,93887,93888,93889,93890,93891,93892,93893,94119,94120,94121,94122)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
93346
93347
93348
93349
93350
93351
93352
93353
93354
93355
93750
93751
93752
93792
93793
93794
93848
93849
93886
93887
93888
93889
93890
93891
93892
93893
94119
94120
94121
94122