SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c72ec0b6ec2f5732799ac5ab97bda1e558e3a7915d1ac1851985c7ef84348328' 
  AND token = 'xgeeYit0xyU3VB5/3CxEhP72OmG1iZLv9IoC3XVD8h4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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