SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4415e17ca8cedd329e9c0a79c269008e8f8888d2070bd90374c9fe6f4da83d1b' 
  AND token = '3/+ZEO0BjasNjKiSyD6izoIXQW23dzt/vBYwmXEW0S0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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