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 (
    19421, 19422, 19423, 19424, 19425, 19426, 
    19427, 19428, 19429, 19430, 19431, 
    19432, 19433, 19434, 19435, 19436
  ) 
  AND cscart_product_descriptions.lang_code = 'ru'

Query time 0.00994

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 (19421,19422,19423,19424,19425,19426,19427,19428,19429,19430,19431,19432,19433,19434,19435,19436) and cscart_product_descriptions.lang_code = 'ru'"
    }
  }
}

Result

product_id short_description full_description unit_name
19421 Case - blower, lower part<p>Part number 97112G9000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19422 Actuator-Intake<p>Part number 971621UAA0</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19423 Fan and motor assembly<p>Part number 97113D2000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19424 Case-inlet duct, lower part<p>Part number 97131G9000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19425 Transistor-Field Effect<p>Part number 97235J5000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19426 Seal (C)-Heater TO Duct<p>Part number 97247B1000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19427 Hose assembly - water inlet<p>Part number 97311G9000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19428 Hose Assembly - Water Outlet<p>Part number 97312G9100</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19429 Control Assembly - Heater<p>Part number 97250G9AA0VCA</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19430 Panel assembly-pillar outer, left<p>Part number 71110G9A60</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19431 Panel assembly-pillar outer, right<p>Part number 71120G9A60</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19432 Panel-side sill outer, left<p>Part number 71312G9D60</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19433 Panel-side sill outer, right<p>Part number 71322G9D60</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19434 Pillar assembly - center inner, left<p>Part number 71401G9700</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19435 Pillar assembly - center inner, right<p>Part number 71402G9700</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19436 Panel assembly - quarter outer, left<p>Part number 71503G9C60</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>