SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37cb49f2af36f2c268b441885f21974accbba90ec3f0f88d773fcd3491037048' 
  AND token = 'lYTOcAQzkj6AhOmiaOd2GG+cdsEk7UJlw2HRHmFNHmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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