SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c16526ac87f1f6ec3613f5a9ce8a8e24594a01363308bd9bedc6708ad76c1d9' 
  AND token = 'Tg5SOudhVD8XchCj1LBG3mj31iqKntehUlA2z7esKC0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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