SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'deae23b18698834434a1656d151583c9f8e643c69e39c69c783da5ed02b7eaf0' 
  AND token = 'Zd+lthczuOeZiQMkCV9L7sZJOBiQjnKV94/+xG1+cjM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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