If you have installed a new PHP version and you are not sure which php.ini is using. You can check with following command:
php --ini
Output in my case:
Configuration File (php.ini) Path: /usr/local/etc/php/7.0 Loaded Configuration File: /usr/local/etc/php/7.0/php.ini Scan for additional .ini files in: /usr/local/etc/php/7.0/conf.d Additional .ini files parsed: /usr/local/etc/php/7.0/conf.d/ext-opcache.ini