SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '520e5cc831e46cf24a9bb01b832731c3ff6f19ac831d83d220c264b66720cff8' 
  AND token = 'ImMDw/awC0OHwbot2ZW9agOHwk8YC/itmOYVcHRb9vk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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