SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f8b4caa16b46f4cdd3e772410bffb0ef1e42bce7d7c3b641735d042595fa528' 
  AND token = 'pqVuLuaDUf5NeGexKO/GETugEN3UIgt25gA/w5Pmuy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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