Stop the execution of foreach loop which extract data from array?

It has probably more systematical solution, but one option is to save the highest recipient ID, and then load only higher IDs next time. Something like this: (not tested)

$last_id = get_option('last_recipient_id');

$rcvr_id = $wpdb->get_results( $wpdb->prepare("SELECT ID FROM wp_users WHERE ID > %d ORDER BY ID "), $last_id ) ; 
foreach($rcvr_id as $rv_id) { 
    $rcvr_id = $rv_id->ID; 

    // your actions
    //... 


} // end of foreach

// if some result was loaded, $rcvr_id holds the last ID value
if( $rcvr_id )
    update_option( 'last_recipient_id' , $rcvr_id );