SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dced124b37059bfc5e3b34007f65c22919962195eb69753b6cb6ca991b8c9870' 
  AND token = '3GuVKK3xdSfs2IHxLQLyC7ABWeuQaYEGCCAKOKbizNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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