SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c957415a8c67b3bad158b93eb2ea05c4d5d7c33e639266683ebf5037ab7dcade' 
  AND token = 'KXth8QBSHYGGOIIRgPujuxqPg9ZU5BXHKRJYQIjDcYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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