SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab705e404efc4d07633c15a16bf91e42829a6ef5063f2fdf67ce9093af73441f' 
  AND token = 'PXPKme7u0hEjVAQCcjDL6flGoFn26AUkLc3R4BstzB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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