SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3e3da3bf09addc3d7ef71173127695ec452cccf82058b7f54453f8a7a0f51df' 
  AND token = 'COkh2vw89a9m375lCPKH3RVPgaklVrNT4lYaxkx1C0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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