SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c02a71ea33ae26b297790aba9a94ce13e3be45cb16c2b0ac9546d7fdb811888' 
  AND token = 'KzTx8w/5fbOhRkb2AvmptRSumfEzQWLWbKxg8+lVdjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

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