SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa95d9934196b535601d3d96545bd6545a690fecd26fd81be4be98e9b7290b08' 
  AND token = 'QnJQKN4eGzB0L4HTqsUudux1WoZaFgFRykQzlHDL4yQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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