SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '352546fd6668f1d2ca4752883f69ed7cb631a63b4d34eab7174b7f8e05df6671' 
  AND token = 'lJYyLIraaCsgPlFb79dA1MsiKXexGpJSiDG7aVZPWfI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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