SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d8bdf30e2349e23b85d828a9b7999dc0e41360c6b2bd130a6dd6c75eb5f8abe' 
  AND token = 'lObw/c8PBrqxPi4um7TBTzVm0DtUBYqztJt3zJKTjYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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