SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c986ff472da4e8b70c41a89e6f67b8ffc82bc4486f0e2bcf9e49bbbee539b56' 
  AND token = '8xyuioRnzvuDwr9EWLk5i0iZu1S43XTZ/jHjZexpJ5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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