SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4a4f7e222d8bc163c4c4fdaea3ade35ef56ccf27a73a7d53db665acc7bfb70d' 
  AND token = 'LzL0bbec+7JgSQO52n2GDzmnryYRZri7LQlIS070CUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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