SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cbfd6c42c727fc0cc48865edda8a1e0db104119f67b679998b89843a894f31b' 
  AND token = 'MO/v1iXHH3hJ4wSCDgkd/B5D5gAN0KYk0LvQLZJ2i1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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