Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '573f283929152bea8cc02706bc3327debfec307ccd4c870701b3c80225c2f240' 
  AND token = 'a/DK4tgzThrE191m2LSE7kSSLU+UZ6nrrwBSkrp0YuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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