SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a5b69e3552acb08202fbebb01744b343f28d87f19981c78926e41b6dfc0f8f5b' 
  AND token = 'qDXAseoQMYsU9iUmpSSAkwSNvqC7Fwt/mUQiOUQD62E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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