Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7bad1efe1db7260e883768e2897cbd9191b091efd3f1a274c7dc4ec4971b4fa' 
  AND token = 'reJGYEBBKlWTNHRhRBCIJVcZE5Mb+k1Lu5AI0t5i9NA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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