SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '514bca544034a302502c704d9f18053a9883a9c75d343c5b77969f649cbb77c2' 
  AND token = 'MfISvzc9tUXwrKHbG73wNeJCM+sB1LHwgPe2PKSTUAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

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