SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fe696da8b5cee18ebf622cdba3656b79fa33ac24595dd020d40b87dcca7de05' 
  AND token = '0QDrKW1Z3I1ZJ46FvyWzLlIE/xKpDBGd6OzSFuAB/gM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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