SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae822418ce74d89575329ec96ce525d7b96045936595b79b4f7972f678a517ef' 
  AND token = 'hVkZSETAhaUb7ilhstgXuArBoXPXBSM24MWieM4MFzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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