SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '363f370a2f8688c8bdc9b53d589d4feecf13637ced84e2d55fa28ed955d66ec8' 
  AND token = 'yKk9VnH1BXJUowNSqVUQNzn+uRrXOWfukBR5CYw5uUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}