SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2463536d20fd81eae60139b951e65c27f3f206d95e5a801d21719f4d0d66d176' 
  AND token = 'TQHABEvtLKciJaVm2bIyYpvXBgn+n7LCOGvf/oaDNF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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