SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '416577b0e4c247e85782902035f30e228c92bd054a7224bf6241ab83a682abe1' 
  AND token = 'mj5Sj2bhzyEZqUviOQe3YwYEblXdAh/IuCQPPwGkT+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}