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 (
    96183, 96184, 96185, 96186, 96187, 96188, 
    96190, 96191, 96192, 96781, 96782, 
    96783, 96784, 96785, 96786, 96787, 
    96792, 96793, 96794, 96795, 96796, 
    96797, 96798, 96799, 96800, 96801, 
    96802, 96803, 96804, 96805, 96806, 
    96807, 96808, 96809, 96810, 96811, 
    96812, 96813, 96814, 96815, 96816, 
    96817, 96818, 96819, 96820, 96821, 
    96822, 96823
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00091

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 (96183,96184,96185,96186,96187,96188,96190,96191,96192,96781,96782,96783,96784,96785,96786,96787,96792,96793,96794,96795,96796,96797,96798,96799,96800,96801,96802,96803,96804,96805,96806,96807,96808,96809,96810,96811,96812,96813,96814,96815,96816,96817,96818,96819,96820,96821,96822,96823)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
96183
96184
96185
96186
96187
96188
96190
96191
96192
96781
96782
96783
96784
96785
96786
96787
96792
96793
96794
96795
96796
96797
96798
96799
96800
96801
96802
96803
96804
96805
96806
96807
96808
96809
96810
96811
96812
96813
96814
96815
96816
96817
96818
96819
96820
96821
96822
96823