SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4cd52f55f210d6ece0c57c43e7231fb997148d8c0a9a6a6a4cdbb057f49a885' 
  AND token = 'd/YRBH6BEtU7jAHtaNgj3UDnqaqeK2rrT+183Fd+R90=' 
  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