SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '879d04816b8bec727e80d9e8d7c817f74284c225b564add079d1bacaec66e083' 
  AND token = 's1IMsTxOwgHHKqeesmMPfEsCf2MluQJjIg0O5ytFXH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}