SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4459fbfede97fb131c37957bb292c7bf94a9be4ebaa3c5600664b82868b43d5b' 
  AND token = 'TCtKM9YTNHhkXqq8L03tf07hN+5Q8Okth1kgrwxIMSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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