SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c0b19ba6fc1e38a5708e7a77c0159e771dd95954f26ca92cf861dcfde7d68b8' 
  AND token = 'K5nG2J+n64glxWgK0FtgLbSsHkBjMnvWGGBgpmG9zlw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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