SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d352cf8b958aa8302346451151be4cc293566bb49e8aa3fcabf737aee4b0690' 
  AND token = 'Ywt4kFciwr2M/aqycsEuX/fmyU+UsO06n86lZZ0I/ZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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