SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2cc252f648977c1ba789d9c3a51a86ba7a58026ce69d611aac1d5c3934b297eb' 
  AND token = 'sLQTPumhouXtUTPWiFEfEFY6ie8Ltq4MZj70149GVHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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