SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1658846111f8f532d5bb74da153349ff93ebd6c79300547d5609bc60bb38eeb' 
  AND token = 'i3xLLQsy436uZLbBrM4cW0zaYy8kZ64THksvJ7WThEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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