SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3148e283f64758ed5351c6eee913dc172f72ae7d506145122239ffc25227bf5' 
  AND token = 'E3fsuUXTtqw+J+a5AuN4V9j4A9H75PE/Oq5bvVNzn2E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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