SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e6eb4dc0c966c35f35e4e09d8df503614f51354e3cf59f2b24be3276c54001f' 
  AND token = 'rX4Db8UOFCw1utuXzwV9ThxYiYFWPT+qKzxbe+QrMGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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