SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8b1bb40946fb65923625a357816faa8da16d9a07e9cfb26de0eb309a8e5b1db' 
  AND token = '2g7ATSf4bXvCVD8M5OydTUS4aAT6qAobCyGMlEcI0vg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00123

JSON explain

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