SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '640245de394da6827d22f402c3374d020e09f6295793896576935511a84a76fc' 
  AND token = 'TLhS790GO7qHzNRanZDtv1Yb6dFcuB3QgX+J/XJCyu8=' 
  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