SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '445e8ffea63d8e6eb63af3d5e540afdba01465a3ce6dd548037561a599d1f0e2' 
  AND token = '92jy7JmlSSG8dEPM4DP8ds43A+lhCy2zVBzDb021f7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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