Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '850cce7bebf105a41188285a9228e5ce14dbc423f62f176c98737c74f8eb631d' 
  AND token = 'RqMJSFI58Ip6RRTPHl4viaJYANemgZhpXE5NfwJdngE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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