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 (
    95611, 95612, 95613, 95614, 95615, 95616, 
    95617, 95618, 95619, 95620, 95621, 
    95622, 95623, 95624, 95625, 95626, 
    95627, 95628, 95629, 95630, 95631, 
    95632, 95633, 95634, 95635, 95636, 
    95637, 95639, 95641, 95642, 95643, 
    95644, 95647, 95648, 95649, 95650, 
    95651, 95652, 95654, 95683, 95702, 
    95703, 95764, 95766, 95767, 95780, 
    95781, 95782
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00098

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "25.69"
    },
    "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": "20.89",
        "eval_cost": "4.80",
        "prefix_cost": "25.69",
        "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 (95611,95612,95613,95614,95615,95616,95617,95618,95619,95620,95621,95622,95623,95624,95625,95626,95627,95628,95629,95630,95631,95632,95633,95634,95635,95636,95637,95639,95641,95642,95643,95644,95647,95648,95649,95650,95651,95652,95654,95683,95702,95703,95764,95766,95767,95780,95781,95782)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
95611
95612
95613
95614
95615
95616
95617
95618
95619
95620
95621
95622
95623
95624
95625
95626
95627
95628
95629
95630
95631
95632
95633
95634
95635
95636
95637
95639
95641
95642
95643
95644
95647
95648
95649
95650
95651
95652
95654
95683
95702
95703
95764
95766
95767
95780
95781
95782