SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b5301168e579be41a5f134a9a1bd1c9b10420a8c4cab8f80969341a087bf1ad8' 
  AND token = 'LnOYW+cRVqd+gv9sBwCHc0IKWgV7FnfT7nPcbJI59kE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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