use HTTP::Date;

my $start_time = str2time('2005-10-01 22:00:00');
my $end_time   = str2time('2005-10-02 04:00:00');

my $check_time = str2time('2005-10-01 22:40:00');

if ($start_time < $end_time) {
    if ($start_time < $check_time
        and
        $check_time < $end_time) {
        print "yes\n";
    }
    else {
        print "no\n";
    }
}
elsif ($end_time < $start_time) {
    if ($end_time < $check_time
        and
        $check_time < $start_time) {
        print "yes\n";
    }
    else {
        print "no\n";
    }
}
else {
    print "Start and End times are identical\n";
}

##</code><code>##

SELECT 1 WHERE check_time BETWEEN start_time AND end_time
or
SELECT 1 WHERE concat(check_date, ' ', check_time) BETWEEN concat(start_date, ' ', start_time) AND concat(end_date, ' ', end_time)