SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a3e05a4496680996bd297b1fe749cedbb003b1c3505d985f3fc9aa627b1b362e' 
  AND token = '5nG9/QzbsGCJgQxENKrvOYiJq/ZwAVsOQBwQH0lsLdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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