SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58617898c7087a9c0c1a67c220598e7f5dc2418959166bd01cc097804f473795' 
  AND token = 'xHRgIqHYwiqpRORE8RAXeirTNlSzcjHjsToJppWw2jk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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