SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '767246985aa4cf576923c07826c90441f5722aaf03e4cd5f3813fdfa1ff25c35' 
  AND token = 'im4t+nVDyyZDgY9xqreWfaUGxJ160Bpqkgc/Mw3VJcM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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