Why sql is loading data infinite?

I have two tables for statistics events, and sessions, here is how they look

Here Sessions Table Showing rows 0 - 29 (4 730 018 total))

And here is events table Showing rows 0 - 29 (3686 total)

Now here is data I am displaying

Now here is my SQL for displaying data

 SELECT sessions.sid, events.datetime, count(*) as num_rows, count(distinct sessions.sid) as sessions, 
    sum( targetbuttonname = 'kredyt' ) as num_kredyt, 
    sum( targetbuttonname = 'konto' ) as num_konto,
    sum( targetbuttonname = 'czat' ) as num_czat,
    sum( targetbuttonname = 'video-voice_btns' ) as num_voice,
    sum( targetbuttonname = 'video-close_btn' )  as num_close,
    sum( targetbuttonname = 'video-muted_btn' ) as num_muted,
    sum( targetbuttonname = 'video-play_btn' )  as num_play,
    sum( targetbuttonname = 'video-pause_btn' )  as num_pause,
    sum( targetbuttonname = 'video-replay_btn' ) as num_replay, 
    sum(watchtime) as num_watchtime, 
    sum(devicetype ='Computer') as num_computer 
from events INNER JOIN
     sessions
     ON events.sid =sessions.sid;

Now when I have small data everything works fine

Now when I have huge data in a sessions table as you can see above over 4 million data,

And try to run the script above in my PHPmyadmin the request never ends and MariaDB doesn't respond anymore, I have to restart the service manually.

What do I need to do to solve my problem?

from Why sql is loading data infinite?