SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b55026ca564c9cc9975c86a15c58e90b72cc2acc08ff4f77da48f49dde3184d' 
  AND token = 'zlahRxZ3HsT1wK0TW6Yq55yz+MLAlbdvajzVMHs2xJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

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