use Data::Dumper;

my $array_from_json = [["ZG NR","Ortsangabe", "Stoppunkt","Rücklaufende minuten"],["ZG NR","Ortsangabe", "Stoppunkt","Rücklaufende Minuten"]];
$array_from_json = [["001","Berlin", "Jüterbog","120"],["002","Dresden", "Riesa","95"]];

my @keys = qw(ZugNr Ortsangabe Stoppunkt Returntime );
my %Fahrplan = ();
foreach my $zug( 1 .. scalar @$array_from_json){
    my %hh = (); # Helper Hash
    @hh{@keys} = @{$array_from_json->[$zug-1]};
    $Fahrplan{$zug} = \%hh;
}

print Dumper \%Fahrplan;

# ausgabe
$VAR1 = {
          '1' => {
                   'Returntime' => '120',
                   'ZugNr' => '001',
                   'Stoppunkt' => 'Jüterbog',
                   'Ortsangabe' => 'Berlin'
                 },
          '2' => {
                   'Returntime' => '95',
                   'ZugNr' => '002',
                   'Stoppunkt' => 'Riesa',
                   'Ortsangabe' => 'Dresden'
                 }
        };