I use exists() if I need to return a value, instead if I need to stop the execution of the script I use findOrFail(). You can use exists() for example when a user open a empty gallery and you want to print a response. You can use findOrFail() for example when a user open a gallery that does not exist and you need to return a 404.

As @lovePizza stated, using the below will stop execution and display an error page if it doesn't exist:

$q = Users::findOrFail(1);

If you don't want it to fail but attempt to run the query regardless then you can do this:

$q = Users::find(1);

if ($q) {
	echo 'exist';
} else {
	echo 'does not exist';
}