SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '459660be5ae9d2115f0595dbcdc42c6147baba77c44fd4b21f99774d85e71bfb' 
  AND token = '0yinmyK7pKhD+CJz9hVn0jQwPSNFMSjv7YR3Gy+A8sY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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