SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '445bfb396d6225e5993c78172834b1da401a5f70b1b9a4a289c325b3f4a99f28' 
  AND token = 'WjZtXx+8sHthuzJEPnRGWBZsVwAeI4Ll7JZTBC4uReI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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