SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77b4e749fc4e3e424d8abaee102856664f0279d0d6cdcec77023db22fff87dd3' 
  AND token = 'jkGJEphThutVKQBAo+yk2IaT+bpcRcbbc6ZJhefmcG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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