SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1747b579a6a4b53bb5c85d4733fa1a4bbc0ff01b6b9b9759dc1f810fc5f1deef' 
  AND token = 'uPhGZBDN81TPCPHMzaDdo2loXGbIjVJBMyAsAPsYm7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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