SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '03e504643c6bf509fcdae041b2585a83410a789fd9033b4c020b3fdb219f287a' 
  AND token = 'N6TF0S8aFohzrXfxg85va0QkCe5AqAFdq/OGKRuHk+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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