SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6c16661d32ae6e2e6c36ae998a10527d3a0d4b73df65cfacecb4687bbcdba1b' 
  AND token = '++r+EHPXyatuDg7A3brDT/rs136ZYTmFQ0oGtU2ByAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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