Why you want to complicate things with .htaccess where you can do by unloading a module in httpd.conf file??
If you don't want Apache to display directory listing, uncomment the line for mod_autoindex.so in DSO support area of httpd.conf file.
If you want other directories to display directory listing but not a specific directory, you have to do with password access to that directory.
Or leave the page in cgi-bin directory which has directory listing disabled.