SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae322b8e47560753a3ea9ede0928062221f140e122f92c50731e686b507e5339' 
  AND token = 'VNMwnyITyuxK7Q4gL1u8V4jnyEUc1sUAp2KwvaY66Jc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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