my %vhosts = (
   vhost5 => [
      'l02duapofqa_r1',
      'l02duapofqa1_d1',
   ],
);

##</code><code>##

if (my $vhost5 = $vhosts{vhost5}) {
   if (@$vhost5 == 1 && $vhost5->[0] eq 'l02duapofqa') {
      ...
   }
}

##</code><code>##

if (my $vhost5 = $vhosts{vhost5}) {
   if (grep { $_ eq 'l02duapofqa' } @$vhost5) {
      ...
   }
}