You can use a list slice to get around the key creation, too. An ugly hack it is, though.

my @keys = qw( a b c d );
my %h = ( b => 'b' );

my @found = grep {defined} (@h{@keys})[0..@keys];

print Dumper \%h;
print Dumper \@found
[download]

Output:

$VAR1 = {
          'b' => 'b'
        };
$VAR1 = [
          'b'
        ];
[download]