MySQL query sometimes runs slow, sometimes fast

General Questions
3

Here is the “SHOW CREATE TABLE message”

CREATE TABLE `message` ( `id` int(20) NOT NULL AUTO_INCREMENT, `sender` bigint(20) NOT NULL, `recipient` bigint(20) NOT NULL, `status` int(5) NOT NULL, `date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, PRIMARY KEY (`id`), KEY `id` (`id`), KEY `recipient` (`recipient`), KEY `sender` (`sender`), KEY `date` (`date`), KEY `status` (`status`), KEY `sent` (`status`,`recipient`) ) ENGINE=InnoDB AUTO_INCREMENT=90224500 DEFAULT CHARSET=latin1;

Any idea what’s wrong?