SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '454dc0c22121a74273a03be6045c73419a5a11d4fd626f8fd50a9721987326f2' 
  AND token = 'Q3nKuo87v5I/uum6uuxPZNuxuvwwyXrmYTvRWrolKeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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