Wordpress, remove record from output?

Question

WordPress

Now the entries are displayed like this:

<?php global $post;
$args = array( 'posts_per_page' => 10,'post_type' => 'education', 'meta_key'  => 'sm-esno','meta_value'  =>'1', 'order' => 'ASC', 'orderby' => 'date meta_value' );
$myposts = get_posts( $args );
foreach( $myposts as $post ){ setup_postdata($post);
?>

The entry is displayed if the custom field sm-esnohas a value 1(this should remain)
There are custom fields:
sm-data- start date and
sm-time- start time.
It is necessary to somehow display so that the records:
1) Sorted by these fields, i.e. first, the time and date of which are closer to the actual ones were shown
(for example, the date and time of the 1st event = 01.10.2018 10:00, and the date and time of the beginning of the second = 01.10.2018 14:00,
so we first display the first and then the second)
2) Remove entry from the output if the time is now (MSK) <= (less than or equal to) 3 hours before the start of the 1st event,
and so on, as there are 3 hours left before the 2nd, then delete it, etc.