为什么将此查询记录为slow_query？

I have the following database:

我有以下数据库：

CREATE TABLE IF NOT EXISTS `musics` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `active` tinyint(1) NOT NULL DEFAULT '1',
  `slug` varchar(50) NOT NULL,
  `movie_id` int(11) NOT NULL,
  `added` int(11) NOT NULL,
  `updated` int(11) NOT NULL,
  `featured` tinyint(1) NOT NULL,
  `hits` int(11) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `slug` (`slug`),
  KEY `active` (`active`),
  KEY `featured` (`featured`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=3339 ;
CRE