SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d7ace5b1618a2eff3297e78c37a5ce9aa61db3a0c250f49e772b6224f1c33f4' 
  AND token = 'dJzC/Eob2lP8sZTrG0CYmVwpSQRImardyX4tGiqzOxI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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