SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21130c6d6c09b56c51a8aeac0f94c86de32193ad44dd30773f94608b34267077' 
  AND token = 'AbkksUOudg0aIjHXzUVJxBQ6bDIus5sexeQQsdVwBqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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