SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8aa6ef2eb675d92d7bbff40b6ccb6f35a2c6bbce30804677f46637bceda8fb59' 
  AND token = '0ml3OoAzslBG8toP+FZxnKYBYk94udBcIlfRIoRxxuk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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