SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f5f8ad7d271688f6c1063bcd5688e88dd175f7f5b502d5804dd4ac7f7321d99' 
  AND token = '6Zn9AK1hbQnLEVh9W/uDb0zMjLaC44iYIlxC71NVBps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}