SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2bf771a834fd14c8c7728c40347a53a71596e7d157324082e895006560b3305' 
  AND token = 'rK2L7td3DJjJZndOF6XDQSFLHDTxiHokNMtwvgkSC+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

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