SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd01b5df3bf22ccaa299d878bf14bc7237bac792b6b8316e6f7c2eddc7dbd4f1' 
  AND token = 'Xep6aKV+qlbLcn5YozwYNy6KMLEBZPCCG2TlHa3zW5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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