SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aaa5e42d71be079b0ce6763a6c9b98ad6fb78a02bd13af7eb060eaeacc96369d' 
  AND token = 'QjXSupyVPGGQebbzUOWIvgYFKlLIMTpseJOzNHGgNmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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