SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a90f452d99c4403411b9e17ba96ea662f2927e86d29e5fd6044e8e9c86774e2' 
  AND token = 'Po8UEHdcS9hHhdn6XuoIcP2eCJlcDwsFmB5qlAgBnMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

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