A version that does the timeout as well:

use warnings;
use strict;
use Term::ReadKey;

my $key;
my $start = time ();

local $| = 1;
print "Press a key: ";
while (not defined ($key = ReadKey(-1)))
  {
  last if time () - $start > 10;
  }

print defined $key ? "\nGot key $key\n" : " No key after 10 seconds";
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