SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab16de51bd3a78ea44eea6b0984564e4e744fb2facddab321ed80b151657c5e8' 
  AND token = 'Lc26tYgDu+tdb1TnDhIiFyy+qS4pMyaTrjDBkKDufc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}