Storing MySQL GUID/UUIDs

From MySQL 8.0 and above you could use UUID_TO_BIN:

UUID_TO_BIN(string_uuid), UUID_TO_BIN(string_uuid, swap_flag)

Converts a string UUID to a binary UUID and returns the result. (The IS_UUID() function description lists the permitted string UUID formats.) The return binary UUID is a VARBINARY(16) value.

CREATE TABLE t (id binary(16) PRIMARY KEY);
 
INSERT INTO t VALUES(UUID_TO_BIN(UUID(), true));
INSERT INTO t VALUES(UUID_TO_BIN(UUID(), true));
INSERT INTO t VALUES(UUID_TO_BIN(UUID(), true));

SELECT *, BIN_TO_UUID(id) FROM t;

DB-Fiddle.com Demo