SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a145040aa4a836d05415f38deed2b1fcfabe3a1b93ea47a24c727bb11234dffd' 
  AND token = 'ugawag/JMjVJ7nIX0kvEEHMqlPCI8OAxqmx9m99BCDA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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