SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e7c856e5a6ba6a15733a9d42310ed5157e1e15962fc80b93581ef06278fdf98' 
  AND token = 'pYhsiygLvV/pTJs6LNNy2wOJioi2utqG5VvtlklfGsU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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