How to update MySQL with CentOS 6 in most unintrusive way - in regard to perl and PHP packages?
For Official MySQL packages: Oracle yum repository for MySQL.
For MariaDB Packages: MariaDB yum repository.


After that, you will be able to update MySQL via yum up to the latest stable version. They only include the server, client and the minimal MySQL libraries.

For details, I've recently written a step-by-step guide on How to install MySQL 5.6 on CentoOS 7 (most of it applies to CentOS 6, except for the initial rpm version and the start commands). It is a very common task because Red Hat/CentOS has very ancient versions of MySQL (and PostgreSQL).