SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a71d30f34bcfd286ad68f5c862d8feeacf3b68bb6f2e8dd4e34d2439920dc6b7' 
  AND token = 'bWvyaxth3PfvbYOmqZsMruQpWNpK3dJYRCuCVgBY7AU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00076

JSON explain

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