SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23a270040a07a6991fa4cf9bbba0b050cde88a452c9df580d652808d4d4fb86a' 
  AND token = '/4mXMt/GUK6qWlCXQB1C0RrfpOwbcYxdGBBa02ouXGQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

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