SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd3426384e4b87cc8b5c9584b12baa47fd9a08996a1a9cdcfbb3d7f02eb5574f' 
  AND token = 'VvQ0PI+Cdfx0dAhGB6yIPZnjKK+mrGkgQ4X1AeOgHqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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