Given:

my @unwanted = qw( schema log );
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You can use:

my %unwanted = map { $_ => 1 } @unwanted;

my @wanted = grep !$unwanted{ $_ }, keys %hash;
my %subhash = %hash{ @wanted };

do_something( \%sub_hash );
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Or:

my %subhash = %hash;
delete @subhash{ @unwanted };

do_something( \%sub_hash );
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Or:

delete local @hash{ @unwanted };

do_something( \%hash );
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