use strict;
use warnings;
my @arr = ([
    {key=>12, pl=>1, lop=>9},
    {key=>12, pl=>1, lo =>9},
]);

foreach my $subArr_ref (@arr) {
    foreach my $hash_ref (@$subArr_ref) {
        while (my ($key, $value) = each %$hash_ref) {
            print "$key: $value\n";
        }
    }
}
OUTPUT:
pl: 1
lop: 9
key: 12
lo: 0
key: 12
pl: 1