SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'bd2490e9c8934ca437bd3678ab067527e0bf98aebda8d24e2ad8b7c289d55e31' 
  AND token = 'W+4sZjsf3s2wk3LFuyu4xYkDM1a8uu7eEK4Yb6wR8Ks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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