SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbe6853188266c300d0bbb785a330947159bd4e5bd6f4a563f3d9175143a0df2' 
  AND token = 'JUMS72fPReBxJRKVjKoSdPfQiUXMKhoEZm0hFw4msUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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