SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1792fd0c69e2227ecd2e851b97f9b5ed14628acab3991118d135955d32006864' 
  AND token = '7Us4QlGWujnUYPZTOSOkehLZsPMLr2/Pg/5WYJCqMcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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