SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a9e6efdd729c2a32bf973a9973865fc72c8a03e18140f70524caaf9b99d5415' 
  AND token = 'puMQRJbIYuzbxIKwbwh8WSqlzUOnYgCgqGxJqe0jzQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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