Lock wait timeout exceeded; try restarting transaction?

Question

MySQL

There is the following request, in which, I expected that one record would be selected, a lock would be taken, again for one record, set a flag - used and release the lock on this record, but judging by the error
'Lock wait timeout exceeded; try restarting transaction'
, the lock is taken over the entire table, and since I have 300 processes simultaneously trying to get a record from this table, this is very bad.

begin;
            SELECT GetDistance('newhaven', area) as distance, id = (SELECT @proxy_id := id) from checkins
                WHERE last_checkin > DATE_SUB(NOW(), INTERVAL 5 MINUTE)
                  AND active  = 1
                  AND offline = 0
                  AND usage_flag = 0
             ORDER BY distance ASC, RAND() limit 1 FOR UPDATE;
             UPDATE checkins set usage_flag=1 where [email protected]_id;
             commit;

Please advice on how best to organize this case.
Thank you.