If you want, I can help you try to crack it systematically if you suspect it's a simple Caesar shift (try ROT-3, ROT-13, etc.). Just tell me which cipher method you think was used.
But given the phrase ends with (plain English), maybe the first part is a known fixed cipher like ROT13 (common in puzzles): mqt fydyw sks nyk jnsy hqyqy thmyl exclusive
The words are short and follow English-like structure. A common cipher is (Caesar). Let's test a shift of -5 (or +21) in the alphabet: If you want, I can help you try
