SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78abc6962ca2c44e940ee9534dcf8fa790fd9a46a8cf1f4225cbeeb6dbc1c70e' 
  AND token = 'NpHZPCVqDBi+vINYXkyKsCR/H30K/MuhSl5b8kqw/Yw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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