SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1b404e93bb5876941f2206604036f68b061d5cc7d70566d33a35929c7fd6744' 
  AND token = 'Eomt8PzTGurZjCvkbkl0TvMb17KWVXsLJFnF0hjaIKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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