SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebec54e2e9084f8671656bcaca3dd3a7388daea9269a2cf79daf2b8e91a70bdf' 
  AND token = 'dltHwVlRBAekAIJEOCqFPeTg1ziCytnS+/8i9D6IEYA=' 
  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"
    }
  }
}