SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '575da3a305474a5d2a45940ebf9e51cc9944da31719169986b78ad0c4acd13e3' 
  AND token = '/hFWlj9gPZKvbENLBSgVADgULil5JHzNm/nuOKQUHVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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