Join function in the query making the query run slower

I have two table both contains data around 200,000. I have write a query like below to retrieve data using some joins.

This is the query I have tried

$dbYTD = DB::table('stdtsum as a')
            ->join(DB::raw("(select distinct s_id, c_cod, compid from stdcus) b"), function($join){
                $join->on('a.compid', '=', 'b.compid')->on('a.c_cod', '=', 'b.c_cod');
            })
        ->select('b.s_id', DB::raw('sum(turnover) as sumturn'))
        ->whereBetween('date', [$startYTD, $endYTD])
        ->groupBy('b.s_id')
        ->get()
        ->toArray();

This query is giving result correct but the process time it takes is very long, sometimes it even timesout.

Can anybody help me how can I optimize this query?

via Chebli Mohamed