SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7d78d2ffa63de1e2942c1955319841b5b2d132d9be35954a821437de42e68db' 
  AND token = 'DQL63R5XVRVbGnVV+TfAh/aSYfBLG4BzqQKEl6e1/5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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