PHP Query需要一段时间才能返回结果

i am running the below MySQL Query in PHP on my web server, the database is located on a separate server:

$sql="select * from call_history where extension_number = '0536*500' and flow = 'in' and DATE(initiated) = '".date("Y-m-d")."' ";
$rs=mysql_query($sql,$pbx01_conn);
echo mysql_num_rows($rs).' Calls IN';

the call_history table has thousands of rows in, is there any way to speed up the query?

Please note: I only have read only access to the database

$initiated = date("Y-m-d");
$sql = "SELECT COUNT(*) as n FROM `call_history` where extension_number = '0536*500' and flow = 'in' and DATE(initiated) =\"{$initiated}\"";
$rs=mysql_query($sql,$pbx01_conn);
$rs = mysql_fetch_row($rs);
echo $rs['n'] . ' Calls IN';

You can also optimize your tables through phpMyAdmin: Tables -> Operations Tab -> Table Maintenance Section -> Optimize Table

Add indexes to the search columns extension_number, flow and initiated.

MySQL is observable slower on searching among several thousands records if there are no indexes.