SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22a50ee68662a8ee1f16df696ad5228b255db17347d1d2006eb137b69284bbf9' 
  AND token = 'UhsCc/RBUt6gzBz5FF+HwHc2/0nFc7bpVwOjY/d5wAQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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