Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4868c7b9c2ad0440dcfc477526eec11b4a168da04f6ee3e02fb8cf3bea9fa21' 
  AND token = 'd1Ga6yqGCO9sytq9oZd1ivyQclmdXu5Un7Xip5Z6d2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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