SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89ff38e96d83e91eb17d818cc9ea0a1e4e015763bbdd77582895217ad2e13525' 
  AND token = 'avLkqidV8XQ5QUFigVLNWU6o1PA/bcPa+OgmOUGdCrY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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