SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '417c30bf1b398b75cfe3098ebe856a0c4f66ed113ac27c619d8bd6f771638161' 
  AND token = 'W3mdVV2nhSzfM/Z3zTo/04kHUFuy0MapPf9Xzh0kjT8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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