SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2534b9515d3d20a0d9bd69720a9b3f7ff3ad38c558d0e5f0b42c6cf87f679713' 
  AND token = 'OfkK9Thy0nylnE9a1SojWSIEVfH5V8bMvpyC+BY49Uo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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