SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26f9b02b8552f74adcd87f15de642b34904ebf4f6ace3642bee8c1c118b20225' 
  AND token = 'zj9w/+hJN/55oFyE7k5ipt8SusuY8lxQhVKWtqdy/3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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