SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bd23e3b5165dd7c7a59dba46e2471f18e94a4cc28d6ead99009aafd10a579d0' 
  AND token = 'PL6cDPt7bgyIVV/eqd4MFN+KVNpreGZxwVrFr8VlST0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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