SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f67932f1427567f630e4e61258e17e039825f971bf3486c42709f265dd527e94' 
  AND token = 'RBGRkgV2ywb9RzN26AOHP+emhDITFEHfCV5eAiotlg8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}