SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '75e433ac05b84f6fd063115061d461a9f7955d62d8bb8e5f3e5b2cb8d65eab15' 
  AND token = 'gNfOQTLgxzMKCBqOJ+IieJs2dX9jGIyBcY21C5TNJn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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