SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e5528d993df5c26ee4847820a6d3dbadc20819b8239b0c4e762137b9a076f06' 
  AND token = 'OLEZA/mk4pHJDbg6CqMdWzsFb6IOBhMvER3T+RPOlQc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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