SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9acef6f44d7788d5ea136215214ddf468149b3865434293978a4211017381ff1' 
  AND token = 'zuECAixIFw2nHjZZyQaoLzSfgHld01spQ1BKF1RNPcI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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