Try this:

SELECT Col1, Col2, Col3
FROKM Table1
WHERE Col1 IS NULL OR Col2 IS NULL OR Col3 IS NULL

Have a look here: 3.3.4.6. Working with NULL Values[^]

Refer the links for similar solution:
Find all those columns which have only null values, in a MySQL table[^]
MySQL find all null values in a DB[^]

--Amit