SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3faee355fba37059e0c2462e1e9272642394c25f1faf10830092bb50cb209696' 
  AND token = 'Ryx7X8/w8EfbRUEYTiLaTe36EyX2hQhI+fPSV0e2T/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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