SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc6d3150efef3c67af0c0f0a71147efff45ba16bf462f607a3ce319915449366' 
  AND token = 'PB9/CPYB1DWxg4MXYngTfFXVM5Cts5XlzFCnYVRnmK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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