SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8b629ca4f9f7cc4334f1cde3b857d6b64149ef673970036efd2365733f4326a4' 
  AND token = 'JsSujDydvkCtdyZPGGTeDuFhW2vRtOws9Jf4XuzVmWM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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