SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc66c8e93e50e86456ca5632f3e5d7427e6f964914f1b5aede588e116bd12d4d' 
  AND token = 'zLsGIip3ZxBciL+whjOUmQluN3xBYjT+32PuKNHRCEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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