SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '113cbcbf28ea5cf43233c17961175462651049765b9066f83bcbddb4a066fbec' 
  AND token = 'TnYkiWHzARJs/bvhHWGb7GO60rPoxuWpzCnJSEOIKsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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