SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ffb9c5d387315ee4715cf01e7487d9c76628f39a3959900ed71186f5a02fcf11' 
  AND token = 'IuE9gGYL85EnopsZIQdLIgwfBriDLh46YCw5wTc/ovI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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