At this point (assuming you connected) you're asking yourself, how the heck you know you've connected securely.

I would check the session variables. eg:

my $sth = $dbh->prepare (q#SHOW SESSION STATUS LIKE ?#);

$sth->execute ('Ssl_version');
(undef, my $sslver) = $sth->fetchrow_array;
die "SSL version $sslver insecure" unless $sslver =~ /^TLSv1\.[123]/;
$sth->execute ('Ssl_cipher');
(undef, my $cipher) = $sth->fetchrow_array;
die "SSL cipher $cipher insecure" if $cipher =~ /NULL/;
[download]

Obviously you can adjust these checks depending on your own personal level of paranoia.