SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4e8f7cc0a151ca598bb2f69f68e70a459d656cb687ba8dda658f56dc4a3bdd34' 
  AND token = 'au+rojIs2TH6AVfVI2zqIP72UdIdUWVLhe22Dm9C0bA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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