SQL date issue when date is not isdate

SQL date issue when date is not isdate

Expiry************ DateEnd**
None ********** 2000-06-29 00:00:00.000
None ********** 2000-06-29 00:00:00.000
september 2013 ********** 2013-06-29 00:00:00.000
January 2012 ********** 2013-06-29 00:00:00.000
May 2020 ********** 2013-06-29 00:00:00.000
2013-06-29 00:00:00.000 ********** 2013-06-29 00:00:00.000
From two column I want pick all dates except May 2020 rows, due to future
date. this is what I have so far
DECLARE @YearFlag datetime
SET @YearFlag = DATEADD(yy,-5,GETDATE())
SELECT * FROM #Table
where (DateEnd IS NULL OR DateEnd = '' OR DateEnd <= @YearFlag)
OR (CHARINDEX(Convert(varchar, YEAR(GETDATE())),Expiry) > 0)
--was using below one to pick January 2012 row but getting error
OR (Expiry != 'none' AND Expiry <= GETDATE())