SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c601d110f755497baadd619392cf9f976aa1f564c903647b0ebdfc63400e77e' 
  AND token = 'tg6J9DxKAwJzLaxPV1joU7hicXDIESAFiGdYQcME6ZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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