You can use symbolic references:

our %hash1 = ("A"=>1);
our %hash2 = ("B"=>2);

foreach my $hashref ('hash1', 'hash2') {
    no strict 'refs';
    print "$hashref:",(join ",",sort keys %{$hashref}),"\n";
}
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Note that it won't work on variables declared with my(). From perlref:

Only package variables (globals, even if localized) are visible to symbolic references. Lexical variables (declared with my()) aren't in a symbol table, and thus are invisible to this mechanism.