SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80231f8eb8fc5e3101c8f9bcad5b643eade4f1a55b697f69366769ee1cfd270d' 
  AND token = 'QTSI/F93rgS1jvKEYLqkQy4RJHYvTdL0AUl4oGf/smQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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