SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6847b7b61aab4ea1a819aa5c4f41570a9445a0323c5b50fdf65770ae8d26584b' 
  AND token = 'xopw9Q5aXiy0kzmYXj7WCuNSPoVsrp68sRzzoOjQ3Vg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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