Just for fun, here's a modest alternative:

  sub scan {
    my ($sentence, $wanted) = @_ ;

    while (length($wanted)) {
      return 0 if ($sentence !~ m/([$wanted])/g) ;
      $wanted =~ s/$1// ;
    } ;

    return 1 ;
  } ;
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which starts by scanning the sentence for any of the wanted characters, and removes each one it finds from the wanted list before scanning from where it left off.

This may, or may not, be quicker than scanning for each wanted character individually -- indeed, that is probably quicker if you could arrange to scan for unusual characters first.

Mind you, you didn't say why you need a smarter solution. Or, indeed, what counts as smarter in this context.