SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25fd5c0c74f67be4eac3127a58c7363d7efd4af81a9b9d1d40fba857f4803202' 
  AND token = 'JPEmBKPgK54BDBP46J0zn8l6/6JrnLfSJis7ilqnJsM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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