SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a1ba9281f32f903610bb3d958b1b175801c3e2341b5fff808cce2f860cfbb26' 
  AND token = 'oUS6cNIZxzZC3Xdk1CWCp4Nhm+YYTIDiW7jXnZAUd9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}