SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '40e700cde09092b8fd5e64e1e740c7024af6a393d3d6f5c4681b495eac4f2fbe' 
  AND token = 'NzrwLnVJQXgcrOHY63cCunBJhZEmx9GvktjtxiWGIDA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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