SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8de6b9a97490924d4a8e8c5391a8ec13c409dc1acde52c78db0eb0bad2210f4b' 
  AND token = 'PUZnLtjp2Jtq6UOrILklluqnxPVaaHI1GaDps+ircgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables