SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b4d3de913311fbcf705a2007f1d44cbe6a2d8233b6ab85db2fd93e918032e64' 
  AND token = '9DSYpFWcF0dOqlzyXCRiuUJ/8xY1jIvnRpcWVD7KBag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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