SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f1952f7775ae0acdc1f47787982d7b542922d06f637e2bd03e42b28e39a7674' 
  AND token = 'XZnydU7hUnYNNqfy9W+lEGGuzmF3WiEhLxySidLbIjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00070

JSON explain

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