SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fcfebd991bf6d5a40d291b9c661b684e9f01d12b42812193fa80eb75af46d02' 
  AND token = 'Z47GGO3TA0bl/O5iBn1nBOlTnEp/dYm7wY1WKyjpvAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}