SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '67efbe7f9f56b28158c3d88fd5ed1c34340bdcb27b5ef7d63b3803b0ee2ac540' 
  AND token = 'jbHATZgQvxW87DWpy7bhUmpBYlA2LGZPVQzA5/aDe9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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