SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8ed38bc936154d25fadba244bb25e14953f5d86d6d556f0103d7111e01e7ef0' 
  AND token = 'XXayay4g/laJKwe2BdOZVIX6OwUC3xLmwWBsGLci9MY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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