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 (
    95375, 95376, 95377, 95736, 95756, 95757, 
    95758, 95759, 95760, 95761, 95762, 
    95763, 95768, 95769, 95770, 95771, 
    95772, 95773, 95774, 95775, 95776, 
    95777, 95778, 95779, 95789, 95821, 
    95822, 95823, 95824, 95825
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00082

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 (95375,95376,95377,95736,95756,95757,95758,95759,95760,95761,95762,95763,95768,95769,95770,95771,95772,95773,95774,95775,95776,95777,95778,95779,95789,95821,95822,95823,95824,95825)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
95375
95376
95377
95736
95756
95757
95758
95759
95760
95761
95762
95763
95768
95769
95770
95771
95772
95773
95774
95775
95776
95777
95778
95779
95789
95821
95822
95823
95824
95825