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, 
  cscart_product_descriptions.unit_name 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    20653, 20654, 20655, 20656, 20657, 20658, 
    20659, 20660, 20661, 20662, 20663, 
    20664, 20665, 20666, 20667, 20668
  ) 
  AND cscart_product_descriptions.lang_code = 'ru'

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "product_id", "idx_product_lang"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["product_id", "lang_code"],
      "rows": 16,
      "filtered": 100,
      "index_condition": "cscart_product_descriptions.product_id in (20653,20654,20655,20656,20657,20658,20659,20660,20661,20662,20663,20664,20665,20666,20667,20668) and cscart_product_descriptions.lang_code = 'ru'"
    }
  }
}

Result

product_id short_description full_description unit_name
20653 Pad-antivibration rear floor front, right<p>Part number 84164D2000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
20654 Under cover assy-floor rear, right<p>Part number 84247T1000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
20655 Plug-wax injection hole<p>Part number 1731825001B</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
20656 Cover - fender apron top, left<p>Part number 84159T1000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
20657 Cover - fender apron top, right<p>Part number 84169T1000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
20658 Partition assembly - engine room lower, left side<p>Part number 841Z1T1000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
20659 Partition assembly - engine room upper, left side<p>Part number 841Z5T1000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
20660 Partition assembly - engine room upper, right side<p>Part number 84192T1000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
20661 Lever-console type, shift by wire<p>Part number 467W0T1150</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
20662 Lever-console type, shift by wire<p>Part number 467W0T1600VC9</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
20663 Indicator assembly - shift lever<p>Part number 46750T1100</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
20664 Garnish-front upper part<p>Part number 84694T1100NDF</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
20665 Garnish-front upper part<p>Part number 84694T1100OWN</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
20666 Console Assembly - Follower<p>Part number 84610T1000NBD</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
20667 Bridge-Front Console Rear<p>Part number 84618T1000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
20668 Tray Assembly - Floor Console<p>Part number 84630T1110RWD</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>