SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '198139501424820cfb4374a9584754b876a0ab5e8b703e6734f7029ad8ee274e' 
  AND token = 'jnbMyQDJuz5Anad+fIOOxiv9Jzl8OrDDbzI96l366I8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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