SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c73da336bddd8d97de295a3e41d93f7ce05052ca680c204a38107720223546c' 
  AND token = 'gvLeYE+5PZoax7ak5+xQIzr9IzaXM52zHl6hjQe7wSM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}