SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd33d6f16e2a49a509daadfa1dd81d4c2e4c17d920a63137fdeef2077efb46a2f' 
  AND token = 'M2yZoLtSSRzfqf2czBpvyem3dZBf7DzVbRcksRnL4WM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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