SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a58df39e8ced375b2ad32052da92d68b03cebaf8707969bf067cbc668cd5ae60' 
  AND token = '2douyoXlUvfeDjj2jtzMN4EDuDOAHh19wx4se3vKjK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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