SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd651ee955e902fcdf13fc8aa9e712da1dcad89b980932e3c6bd79ddecf6ff41c' 
  AND token = 'k1hGTS7rPLhK/VVBk+fMFisILOOaUXYi2O6zFUJfmGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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