SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0eafcb8dc56685578fd54417e42ece5d1aa94df5ccb86548c437bca9425beffd' 
  AND token = 'YWk5TzrIYwEmmgK5D8cxJsWuG1iUZYPE0LR7/DwKevI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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