SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '865303d005c2344180df3dd3e4b416737c93b1332349bc20bf74ca36601cc9cb' 
  AND token = 'hN0OXtg5RRTRYnQlONwh+5GPkImOkecLye961hXQKX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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