SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47aa4a3b8cc54523e9947dcf6af7cf82b0ca56de6ce743d9e03dbe60a214f7fb' 
  AND token = 'PYcsj7/HnXxM7+dKj9BkrQk3CtX8IKsxdGbSdCcBxYc=' 
  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