SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '3bb042633912f99ca5bc5147604efeeca3034043b4cefb2bab90f03a282ee82a' 
  AND token = 'IfexlwHtI/ZniFGCpASlZqHU8Okvv0i8tfloJSuKACM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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