SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fdd25f44d1071e849892c9cbd75a5a6778bd13f0f9bb458ac1ee68b3d65fe72' 
  AND token = 'Q+R3sABOMRKDqApZ++DlBnrjuV6C0lyOyupQwe5DeRQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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