1. Verify the hostname on your server is set correctly
2. Download the MySQL RPM
wget http://repo.mysql.com/mysql-community-release-el7-5.noarch.rpm -P /tmp/
3. Enable to RPM
rpm -ivh /tmp/mysql-community-release-el7-5.noarch.rpm
4. Install MySQL
yum install mysql-server
5. Start and Enable MySQL
systemctl start mysqld
systemctl enable mysqld