SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98e2026f3b90310b878c230b9099035359a42729258a176bb9a403fec979e4b0' 
  AND token = 'Rmbxa/lmBADKaMJ/t9TmrssFi3TZS49nRWccmmCuZLM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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