SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7f76064e3b8a091d57a086e879547726f4b67e9966f248bb81d7e08fb713b794' 
  AND token = '3ERlYeuJi3gOv26FQH9YJ24KkGCB/EAOMEXD0FtJ4Sc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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