SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bf9555bc8539b775a1de7433603958cc0f6916662c64f4baf9d5130e477ddca' 
  AND token = 'LfP7r9Rxgtm+Bjr85RbXeL6VaSyHZI8VQPnJgMH9Uy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

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