SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '5f2abc351be9fef7bf81676a8aec901b801fa272cd33a2f8966ac15f3deb4449' 
  AND token = 'DFfVmMHa+lC/WqfyGX0yrJrQGvn+mYyAkGENwIYi5VE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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