SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad9246dac50711d7365823ce93078a2cc6d84688833b8f55ea23fb36f20b5f95' 
  AND token = 'a37TnFWda64skHhzcKTc0swcu9LNB/B9qPKR+ipKdw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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