SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b24e0904c78d72a36d115beff797e65c7f9e785ecd34eda7a42fb0eb4f22fdfe' 
  AND token = 't4mzenNgK9LwActIm9+Y9J6A3S6M0JugTxlQBYsyW9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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