SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5180f72c49deaa7bcf4ccab3fa6c9521dab37fb0aae922aa92e927fc60a0a50' 
  AND token = 'BOjAmXmAz55xeS6AKpgIlGcIyudpunbPDToAsjJI9ts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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