How to skip prefix column check in multi column index in MySQL?
It depends.  Since you are using MySQL 8.0, the index starting with type is probably fine.  I am guessing that the optimizer will be smart enough to 


fetch rows with (0,1,15)
Continue fetching, now for rows with (1,1,15).


You can get some clues from EXPLAIN or EXPLAIN FORMAT=JSON.

You can 'prove' that it is (or is not) doing it in that optimal way by this technique:

FLUSH STATUS;
SELECT ...
SHOW SESSION STATUS LIKE 'Handler%';


If the total of the Handler_read_% values is very close to the number of rows returned, then it probably did it that optimal way.  Else the Handler_read values may be much larger.

I see no PRIMARY KEY on that table.  If that triple is 'unique' then make it the PK.  This will speed it up a little more due to "clustering" of the PK.

If the index is not good enough, rearrange it to have type last.

(Pet peeve:  Drop the constant "post" from column names; it clutters queries.)