SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b9be91f9f62986d1ba17fdc15f757dfa8e1f3e1606e387b2c4bab314fc29889' 
  AND token = 'PXmqnmeem86W2Potm+IVuUjyVal6ffr0K0gsOuPM9uM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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