This config is close...
<FilesMatch "\.(php)$"> Header set Cache-Control "max-age=7200, must-revalidate" </FilesMatch>
...but it does all php pages, not just the home page like I want.
Basically the developer said he wants example.com to be cached, while:
would not be cached.
Note the developer is using pretty URLs with an MVC framework that runs everything through index.php.