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 (
    18253, 18254, 18255, 18256, 18257, 18258, 
    18259, 18260, 18261, 18262, 18263, 
    18264, 18265, 18266, 18267, 18268
  ) 
  AND cscart_product_descriptions.lang_code = 'ru'

Query time 0.00100

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 (18253,18254,18255,18256,18257,18258,18259,18260,18261,18262,18263,18264,18265,18266,18267,18268) and cscart_product_descriptions.lang_code = 'ru'"
    }
  }
}

Result

product_id short_description full_description unit_name
18253 Auto Transaxle and Torque Converter Assembly<p>Part number 4500047MG0</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
18254 Hose Assembly-Upper<p>Part number 2545047200</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
18255 Hose Assembly-Lower<p>Part number 2545147200</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
18256 Warmer-A.T.F<p>Part number 2562047200</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
18257 Bracket-Air Breather<p>Part number 4527547100</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
18258 Plug-breather hose<p>Part number 452724E000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
18259 Case assembly-automatic transmission<p>Part number 4524047550</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
18260 hose-breather<p>Part number 452734F200</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
18261 Support assembly - center<p>Part number 4532047000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
18262 sleeve<p>Part number 4524247000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
18263 Piston-Brake<p>Part number 4567047010</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
18264 Clip<p>Part number 452714C000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
18265 D-ring<p>Part number 4567247000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
18266 D-ring<p>Part number 4567347000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
18267 Road Assay-Parking<p>Part number 4592547110</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
18268 case assembly<p>Part number 453304J000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>