id  name    state   date
1   Alice   1   23-03-2018 12:41:31
2   Alice   1   23-03-2018 12:41:42
3   Bob     1   23-03-2018 12:42:18
4   John    1   23-03-2018 12:42:19
5   Alice   2   23-03-2018 12:42:19
6   Alice   1   23-03-2018 12:43:35
7   John    2   23-03-2018 12:43:36

3   Bob     1   23-03-2018 12:42:18
6   Alice   1   23-03-2018 12:43:35
7   John    2   23-03-2018 12:43:36

SET @@sql_mode = "";
SELECT *
FROM `users`
WHERE `date`  > (NOW() - INTERVAL 20 MINUTE)
GROUP BY `name`