SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ccc87d2775f61cd6837c656d2f5417a10cb6bcb217688ec042fa3d376d85465' 
  AND token = 'zIW/gsYtLv9j85v3vwx0sWYiUMOoCPDuhvKVL6Q4qjM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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