use strict;
use warnings;
use Time::Piece;
use Time::Seconds;

my $date_from_db = some_magic_function();

my $one_hour_ago = localtime( shift( @_ ) || time ) - ONE_HOUR;
my $db_date = Time::Piece->strptime( $date_from_db, '%Y-%m-%d %H:%M:%S' );

if ($db_date >= $one_hour_ago) {
    # process
}

##</code><code>##