SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0f5701bee6fd277ab02091f657dd8dbd4d3b7af5c2c046637a65e26e5306508' 
  AND token = 'OGjtdsLrYcXUj4o8DTEKJBSlUwGgtLU/KoNlfygmjz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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