sub whatever {
    my %params = @_;
    lock_keys %params, qw/ key1 key2 key3 /;
    say "Got key1" if $params{key1};    # ok
    say "Got key2" if $params{key2};    # ok
    say "Got key3" if $params{keye};    # Oops - BOOM!
}

whatever key2 => $value2;
whatever keyq => $value1; # Hash has key 'keyq' which is not in the new key set

##</code><code>##

use Getopt::Long qw/:config bundling/;
use Hash::Util qw/ lock_keys /;

our %OPT;
my @OPT_SPEC = qw/ help|h version noact|no-act|dry-run DEBUG output|o=s /;
GetOptions \%OPT, @OPT_SPEC or ($OPT{help} = 1);
lock_keys(%OPT, map /^(\w+)/, @OPT_SPEC);

##</code><code>##

# Option 1: use Params::Validate

# Option 2:
sub whatever {
    my @param_keys = qw/ key1 key2 key3 /;
    my %params = @_;

    $params{$_} //= undef for @param_keys;
    die "Invalid usage" if @param_keys != (keys %params);

    lock_keys %params;
    # ...
}

# Option 3:
sub whatever {
    my %expected_params = map +($_,1), qw/ key1 key2 key3 /;
    my %params = @_;

    for (keys %params) {
        die "whatever: Unexpected named parameter $_" unless exists $expected_params{$_};
    }

    lock_keys %params, keys %expected_params;
    # ...
}