It is written in Laravel 5 documentation that php artisan config:cache stores all the app configuration into one single file which makes the application load fa
You can't stop the caching of config files since it doesn't happen automatically. The only thing you need to do, is not call config:cache.
The file itself can be found in bootstrap/cache/config.php.
Note that the location of the compiled config file has changed recently. Yours might also be in vendor/config.php or storage/framework/config.php. With a fresh install or if you run composer update the file should be in bootstrap/cache though.