SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '926916214ed8c845bf36523074a58ed1164c2029cd2e71ccaa86248e6b879d72' 
  AND token = 'aotb+lGn0dug8sTcm+T0TunepUfGWnjOMh5JYBBDAPo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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