SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68ac557e0f6e5a4954733520c0cb2bcab63725749ddf41bb9188292a06cc8fd5' 
  AND token = 'Fu5BE/k4yutRZaDInhUGVDsyJCxZuSEkX6saTvx3eSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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