SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2e797786eefd44795d5d16d039384256b6fc002daedb8d089d250e4b812b5e2' 
  AND token = 'yRVJZCKDKWjo8rJdzB52MjMumlsq9NNbZSQJZRheH4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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