Unless I missed something I think there are only 4 possiblities.

my $queries = (
"SELECT * FROM or_mod;"
"SELECT * FROM or_mod WHERE upper(component) = upper(?)";
"SELECT * FROM or_mod WHERE upper(env)       = upper(?)";
"SELECT * FROM or_mod WHERE upper(component) = upper(?) AND 
                           upper(env)       = upper(?)";
);
my $sth; my @bind;
if (defined($query{env}) &&(defined $query{component}) {
   $sth = $dbh->prepare($queries->[3]);
   $sth->execute($query{component}, $query{env});
} elsif ( defined ($query{env}) ) { 
   $sth = $dbh->prepare($queries->[2]);
   $sth->execute($query{env});
} elsif ( defined ($query{component}) ) {
   $sth = $dbh->prepare($queries->[1]);
   $sth->execute($query{component});
} else {
   $sth = $dbh->prepare($queries->[0]);
   $sth->execute;
}
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I'm not entirely sure that is much better than dynamicaly generating them, or better at all for that matter. In fact I think the dynamic solution is better because it is dynamic. BTW newer MySQL caches all queries whether you ask or not, I don't know if that holds for bound queries as well. If it does then as long as you are binding, even if it seems lame for this single call, it will give you benefits in the long run.