SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e1e21f09354011429ab7117c4ac1fb7887bb9ab85cab9c5c3d9b5b5df95378d' 
  AND token = 'LLE3aq6SLQxZY5338QjwLYK8TyuLVxJhpogO+VNsGLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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