SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a4ca5ebb8c41e819153eaeb55a23a37457d90349ec562c82a79c82fe322f7fa' 
  AND token = 'ktmrMV89vBGqim9ooIr7BsS4eHxRBhu/IeOJMg/bRX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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