SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58ef97a3724b5806828f3dda34e2d501ecd47d0f9ace27b69d44568ee47be849' 
  AND token = '99zGdc0F2mA/Vkn9AirjNiicfVwvQiZkrxJk64yhbxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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