SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '252266b31b492f0bfe2d76dfe130c82807a1b8d6721fdbf59f8544e2a407dbd5' 
  AND token = 'uw8beJHQK58tHYO9Ceb2ANTnAj9y8/FN7/P9u4YPeXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

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