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 (
    86475, 86476, 86751, 86752, 85351, 83024, 
    83025, 90860, 90861, 90939, 90940, 
    82810, 82883, 82956, 83330, 83340, 
    82593, 82595, 83356, 83358, 91112, 
    91198, 91253, 85287, 85288, 85384, 
    85385, 85435, 85436, 85486, 85487, 
    82590, 83349, 85333, 85334, 86473, 
    86474, 86749, 86750, 91143, 86631, 
    86633, 86700, 86702, 84875, 84876, 
    84877, 90738
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00101

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 (86475,86476,86751,86752,85351,83024,83025,90860,90861,90939,90940,82810,82883,82956,83330,83340,82593,82595,83356,83358,91112,91198,91253,85287,85288,85384,85385,85435,85436,85486,85487,82590,83349,85333,85334,86473,86474,86749,86750,91143,86631,86633,86700,86702,84875,84876,84877,90738)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}