SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eaf31361225fd22177690f257b37ac6d976e6077b452009c9905ed345d74a042' 
  AND token = '/PSfTB8GzHuAO2aJwnQv0F/+v6DcWNuPjGRZa05MO10=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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