SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1d9aadcc8b8888a690588f95de4284f52cfef5a9755db113e472e360672f363' 
  AND token = 'WY0CdEWXBUORFEQx1FdVghJdQCpaFfi76lrds1HElhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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