SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc3aa628e00066814b9cc905f4d73e2a7e37c807d588b26cc2cd51de5589a384' 
  AND token = 'HuLa8KuaQZO7WxsGyTxUFChHdL3TX+/EyS9XU+Uex9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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