SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29406470e3b6011e5dc9ccd4a4fc3c47442ffd2fa26f7d61538c249b9d1ffa25' 
  AND token = '+/Rips0BmV4gvOlg5z5pCQXZfajyhlu7ffrLDoM3yOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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