SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '927501b515e15d101416b9efd3ac3f13f666b624fbe884b52c1223b467922484' 
  AND token = '0MUlTbOfIqAWgPzZitiIa0T3vtTGyeRgUS2yIJ5OlqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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