SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f4cc3d30e706d6ad0cb324ec7114addc641b8d0eb2384930cd3de7f96a73e71' 
  AND token = 'dMJiVJtNesxqpSHggd9rsz0hrrVGh0m0TEgGKJ9wQ4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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