SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e90eaa01fa0723bfe59d818c93479b98ce4f4bc5f208a33dd896a77ad594151' 
  AND token = 'yKXiSvZd/0A3J5km0bESYFG6dtoCkzipavUy2mfqtcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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