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 (
    95644, 95647, 95648, 95649, 95650, 95651, 
    95652, 95654, 95934, 95935, 95937, 
    95938, 95939, 95941, 95942, 95943, 
    96206, 96207, 96208, 96341, 96342, 
    96343, 96344, 96345, 96346, 96347, 
    96348, 96601, 96602, 96603, 96604, 
    96605, 96606, 96607, 96608, 96609, 
    96610, 96611, 96612, 96613, 96614, 
    96615, 96616, 96617, 96618, 96619, 
    96620, 96621
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00088

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.62"
    },
    "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": "16.82",
        "eval_cost": "4.80",
        "prefix_cost": "21.62",
        "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 (95644,95647,95648,95649,95650,95651,95652,95654,95934,95935,95937,95938,95939,95941,95942,95943,96206,96207,96208,96341,96342,96343,96344,96345,96346,96347,96348,96601,96602,96603,96604,96605,96606,96607,96608,96609,96610,96611,96612,96613,96614,96615,96616,96617,96618,96619,96620,96621)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
95644
95647
95648
95649
95650
95651
95652
95654
95934
95935
95937
95938
95939
95941
95942
95943
96206
96207
96208
96341
96342
96343
96344
96345
96346
96347
96348
96601
96602
96603
96604
96605
96606
96607
96608
96609
96610
96611
96612
96613
96614
96615
96616
96617
96618
96619
96620
96621