SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00152468f9b557d46f6989132ed9b53998d3be7f858e3fd7a7e2e9d4d2f7aa69' 
  AND token = '3wZEllVaNkhCSUJ5gWezyiAy4SnsccFKGpPbOCPBm9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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