SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0806454d5ce4ed5daa63a2760b498ca5e93faf936cd2e5e1b7948e8b3873576b' 
  AND token = '6PzrqQpuYOVZJ/swbd4yi86tfsC8HS8CLEHdGKcQX8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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