SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e1d95bc3aac412d4a621cdaa557f871e69f151ab333a9e8d9a25af3781d6870' 
  AND token = 'RGbPsnW8pUJy1MaFoIFnBFqkxSsmtsKTD6a5OHw7SfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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