On OSX 10.8 and on, the control for MySQL is available from the System Configs. Open System Preferences, click on Mysql (usually on the very bottom) and start/stop the service from that pane. https://dev.mysql.com/doc/refman/5.6/en/osx-installation-launchd.html
The plist file is now under /Library/LaunchDaemons/com.oracle.oss.mysql.mysqld.plist