Because I see lots of processes there, and also the "time" column shows large values its them.

You have to kill them 1 by 1, MySQL doesn't have any massive kill command. You are able to script it in almost any language, for instance in PHP you should use something similar to:

$result = mysql_query("SHOW FULL PROCESSLIST");
while ($row=mysql_fetch_array($result)) {
  if ($row["Time"] > 200 ) {
    $sql="KILL $process_id";

Be cautious you do not kill an optimize table query because you will hose that table.

Browse the first discuss the mysql ref guide for that kill command. It possesses a helpful script.

from directly within the mysql interface? you cannot. you will need to write a script in another language or perhaps a saved procedure.