SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8209f0adbafb3ab14603ec2f7a39166750b1b437068e26bf1f642e758e38838c' 
  AND token = 'hlVbS8SjB5nJS1hRUwNtBsacUmSnx3cubOz118O4VcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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