use URI::Find;

my $search = '1001_.jpg';

my $found;
my $finder = URI::Find->new(
   sub {
      my $uri = shift;
	  return if $found;
	  say $uri if ($uri =~ m/\Q$search\E$/ && ++$found);
   }
);

local $/ = undef;
my $line = <DATA>;

$finder->find(\$line);
__DATA__
http://site/images/I/61cbCGzH1hL1._SL1001_.jpg
http://site/images/I/710TxT7aX0L._SY355_.jpg
http://site/images/I/61cbCGzH1hL2._SL1001_.jpg
http://site/images/I/61WBOyRAhNL3._SL1001_.jpg
http://site/images/I/41c3CszH1hL4._SL1001_.jpg
http://site/images/I/61E9RFObPiL._SX522_.jpg
http://site/images/I/71cbCszH1hL5._SL1001_.jpg