Insert if not exists MYSQL 5.5.24

[Leandro Rodrigues]

Hi,
I would like to make a query that allows me to enter data only if registration with aqueas conditions did not exist.

already tried this:
INSERT INTO descriptor
                          (texto_descritor, cod, codTipoDescritor, cod_Idioma)
VALUES ('Church of the Third', 1, 'tit', 'en')
WHERE (SELECT count (*) FROM descriptor WHERE cod = 1) = 0


And also:
INSERT INTO descriptor
                          (texto_descritor, cod, codTipoDescritor, cod_Idioma)
VALUES ('Church of the Third', 1, 'tit', 'en')
WHERE NOT EXISTS (SELECT * FROM descriptor WHERE cod = 1)

However none of these work.

Someone can help me?

Best Regards