SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78e109033b5c0df223451c6a42984aba69956d32e7a97dfee280b1e3e94ed854' 
  AND token = 'NdnB0yawepW7gRiJXGzwI1oEXkfxacTewn7rEGUGI7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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