SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e5deb11d411be610d0d11fed6d44eebf57d4f3ef73ff162df9865868623afee' 
  AND token = 'raLcpVuIOiB/Wwn39nCIgCDIDxOgACSgZQvXWOf9c7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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