SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a47209834769acb5f151225bc87fe0201c2cc0962d0a1244c17726701ff710d5' 
  AND token = 'V2QcAh4BEY1ERl/d2iFifSKD93mW15mGDWjyh1bN2o4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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