MySQL Stored Function to generate Unix timestamp in milliseconds (UTC/GMT)

getUnixTimestampInMilliseconds.SQL

DROP FUNCTION IF EXISTS `getUnixTimestampInMilliseconds`;

CREATE FUNCTION `getUnixTimestampInMilliseconds`()
RETURNS bigint(20)

BEGIN
  DECLARE milliseconds BIGINT DEFAULT 0;
  
  SELECT CONV(
	  CONCAT(
		  SUBSTRING(uid,16,3),
		  SUBSTRING(uid,10,4),
		  SUBSTRING(uid,1,8)),
	  16,10)
	  DIV 10000
	  - (141427 * 24 * 60 * 60 * 1000) INTO milliseconds
  FROM (SELECT UUID() uid) AS alias;

  RETURN milliseconds;
END;