How to use PHP-CLI
You would call '/usr/local/bin/php' if you need the php-cli binary, and '/usr/bin/php' if you need the CGI variant.
If you call 'php' only via the CRON, you're going to end up using the CGI binary, since '/usr/bin' comes first in the CRON $PATH.
To use use php-cli you need to use the path /usr/local/bin/php