SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c92a80d19bf3f463604d778a865d8a6f1c558d1b0ee903fa7cec80bc90478d80' 
  AND token = 'yC/o58oqRWJSvdAXK0uDWItd6QjWQ4cq2iQZTTDMp2c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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