SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '281f7f6f64fec23071ad8d8b4d90f78edfdde044bd74cd027337be86acaade74' 
  AND token = 'cUe1peJ5RxgYuCdRGSpsn6gHMisugr/mxlzj1TU1UrQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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