SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69f608b84084c487b4506a55b868c303a749d83be0bf66a31b57ff0c64eae7bf' 
  AND token = 'MBLEoc5TZnCy6li3zN/Ll/aQcr+5uhED3r7LckVFXK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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