SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93837d59b8d438f705bd16140f7548bd43d928e7769b5e3f0960c36a984f1213' 
  AND token = 'c2H7KFXz6r2xzqeA+YMwTVRbKjqjshpgV+tfF4Jpqh4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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