SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '567031b16b0b91c59b34effc10a29768fb0c0deedad62ca642c325915e60d51f' 
  AND token = 'eMWPhjsKUulb85y24tZMGkuenjg0q85tiNpyNOebyYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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