SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43ad33b89741057c231b45ea94571dfcfc4bfb96a56757ffc72848475442fe99' 
  AND token = 'qCe2DqP725009FwvSjP7+/PGZu3dK+hJBZkGeQE0uoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}