SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '590c0efe82309a453564a067f847ef7850804b693151f4f138553d6d08992806' 
  AND token = 'Zo+OmUS0tyfFcQc5sJ404e85hTJD68Foss3gkgaAzjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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