SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '915952846b6d3a3bb5257b32040fbe872afec6a90ee563ab928e6a4688b1693a' 
  AND token = 'AWEfgz9ulkN/u48nGQhKuaIbU1m8XZd9Vf7SJ0f3rIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

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