SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39d22d755be4556b27a8d6eb1723bcf55f2382651d96f166397b57b3c437352e' 
  AND token = 'mT9tFb0lBz+4SWDx5HIhKzv8zw9S499LbnfE7u0FFv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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