SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b8dc231f2540505904fbe6a05ea475009cd8353e999a9a0a52c575a46b7565f' 
  AND token = 'fWR4EHJyO5WIyIvVbPV9zuwo950D4A5gs3cjqmU0XEU=' 
  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"
    }
  }
}