SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1c825fe5e0113b7f49c906277043edd906e39083f2bdbacfbffcd233f8a9eb4' 
  AND token = 'mB0GNdxhO7BfwQoK2OXRTR3DGqvrCJ5Rsw7WbnPbsV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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