SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da883b2657ce96d1a8962936d9c5b4f93868d5f2436c9da4e87667ea317f48f1' 
  AND token = 'orm4R71KW+xBk2qgRj2qGmyyn3JzuJClYV0yS6IVe5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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