SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0cfeb5e269e4a690df5f85949ef9cef9d80c3d6221730252998e24e4cb3d408' 
  AND token = 'QZ/hVS6YJl6bkCxqHaidXx7nh9Gj/CKNlqFLBgluxUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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