SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e54bbf17ce8bb4f6ee207ad5581ffdb5a5312b903983ccbdc81790e728ebc6b' 
  AND token = 'Bp4cD3bL9joLbkY/uRNYyd9jT4eHCeB8GBDmZMnP+kU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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