SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3570235771b3974db97552c8e52970cef469129ad74f41c895ac62474a600efa' 
  AND token = 'DfrSxqtn/bBwJqvyfKV9JuBOlc+kKgwP8rW9S2DUX8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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