SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c85f37a71a234781a871147d5fc853a7bcfd8acac15f6d06fdcdb2b39a182d24' 
  AND token = '5gLjLLu61JsPb26bQ7nHEMfjs7/2dnpZhXBMR+BWJTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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