SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a06d1cfac64ff0db461a8bce68fcda817934dd11c7b0e25a23038a1bba8de4de' 
  AND token = 'NwnOnhxOmDLNJ+YrRiXiFGFkTi5WiVdEuJleeokw4Jo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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