SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77c1193e994f581dc99156041dbe56a490179bd93cc3ecbb22906e3685dd69f4' 
  AND token = 'hCnpw8xvPSCs08ANl4MY6q8RAfl2YiHm9mORIZakKX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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