SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ceca41ba23bff4bb0433036468be7717ccefa58277836dda63e4739c6408fb7f' 
  AND token = '5ZTK3ilqqPBKFHCbo61Rc7Lw7MolrCzNeuORUNj+hrM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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