SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02258c712895ca1db55db0ecb63976a7bba90dadf4453f658ddb02cb78953d5b' 
  AND token = 'k3KuU8S5G+/mamJRDZQNG9aK9CvoxTOi//gV7RgMqZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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