Slow SQL Query Performance

string sql = "SELECT t1.date, t1.name, t2.name, t3.addrs
             "FROM tbl1 t1 JOIN tbl2 t2 ON tbl1.id = tbl2.id
             "JOIN tbl3 t3 ON t3.addrs = t2.addrs WHERE t1.date = '2013-04-01';";

string connStr = "Server = 10.10.10.100; Database = mydb; etc...";
MySQLConnection conn = new MySQLConnection(connStr);
MySQLCommand    cmd  = new MySQLCommand(sql, conn);
MySQLDataReader rdr = null;
DataTable dt = new DataTable();

dt.Columns.Add("Id","FirstName","LastName","Address","Date");

rdr = cmd.ExecuteReader();

while(rdr.Read())
{
  dt.Rows.Add(rdr["ID"], rdr["FirstName"], rdr["LastName"], rdr["Address"],rdr["Date"]);
}

conn.Close();
rdr.Close();

dataGridView.DataSource = dt;