SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b74fb106c47a877b3933c5dad88126d9f1425c75772050e2c2586e62db68827' 
  AND token = 'fZ+Z2ZpMvm3B/WyHhLG/zPsPyXHZHTjfHuLnQAtOQXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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