SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e73ef30088cb5df854c177c0b43d904cae48765fdcc075ff686bb159ec388c9' 
  AND token = 'FOS/Pqd2zXLTKz0GztpnE4dnF2kaYfPj9AdehXq+Zf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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