SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9114eac028b9b9fa0b1b68a24a7334ce731164951df599e071409eec964ed3aa' 
  AND token = 'RtmY45Ez78qAHVmAHevRXNT+qNdXcwhrIArUZi5XLpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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