SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '799cae48f0d480a2c0e95fecf0ecf660eb205616bff27e63f7d3635c2db7d9db' 
  AND token = 'AqqXzgS94HaWovDnijW4b7JcxwheKByvGZLJtoLE5IU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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