The mod_rewrite module is enabled by default on CentOS 7. If you find it is not enabled on your server, you can enable it by editing 00-base.conf file located in /etc/httpd/conf.modules.d/ directory.
vi /etc/httpd/conf.modules.d/00-base.confAdd or uncomment the following line
LoadModule rewrite_module modules/mod_rewrite.so Service httpd restart