Seems I found a solution

    use BackPAN::Index;
    my $backpan = BackPAN::Index->new;
    my $dist = $backpan->dist("MIME-Base64");
    my $releases = $dist->releases;
    print join "\n", map { $_->version } $releases->all;
[download]

it uses BackPAN however (i.e. includes obsolete versions). But for me it's not a major problem.