SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25a327a48eda02defdf0658b9935d689cbbf59a9f87d0436b931caa243cf31e7' 
  AND token = 'STjWWAqpF338k+7PBSzipG7Tha6w7oV4IxXmpfLaiBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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