SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4d9ab1023fc0114c5860935c8d939934e4a3ddebd5ea0521a4b54b8ee7d006d' 
  AND token = '8dpnV3OmeSl5tfbG2edL2y2tjf+W/8ISs5Lt1BdUKh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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