SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fb9af4a99c9b1068cb8b9ed5ddbb823d35d582df9ff466b531a7ef1946b668d' 
  AND token = '6njmH9JjrLkCZBTv1HCiEEBKunsnILKhM77xlfVQwCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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