If the numbers in your @array have relatively small values (say less than 10**6), and are relatively close to each other, you could trade memory for speed thus:

my ($i, @a2);
$a2[ $array[$_]  ]=$_ for 0..$#array;

for ($i = $find; $i >0; $i--) {
    last if defined $a2[$i];
}    

print "Method 2: $i \n";
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