another approach is to use an intermediate hash and the  delete built-in.

C:\@Work\Perl>perl -wMstrict -e "my %h = qw(a 1  b 2  c 3  d 4);  
my @not_wanted = qw(b d);
my %wanted = %h;  delete @wanted{ @not_wanted };
print qq(key $_ => value $wanted{$_} \n) for keys %wanted"
Outputs:
key c => value 3
key a => value 1
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