use Carp;
my %FOO_KNOWN_ARGS = map {$_=>1} qw/ quz baz /;
sub foo {
     my %args = @_;
     $FOO_KNOWN_ARGS{$_} or croak "Invalid argument '$_'" for keys %args;
     # ...
}
foo(quz=>1,baz=>1);
foo(quz=>1,baz=>1,bar=>1); # dies