SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de9b348986b052fbef5797202651d814d3d1370d99207d11f8d4a7eb5583b455' 
  AND token = 'DPMGPuSH2hvM1sBAm9+WCYxWATU58HmanVJ5W6qKmso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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