SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0492b8997d335cac1237aef9e28166fe81391b41587fa51bd67ee24a4b8f93a7' 
  AND token = 'YqLCi+SWDLUpGznzgaf6qgP/WT7KbbCfYahEBlA+aAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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