SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f800bdc0df29e239d9040ba5b8095e2ec1b02d4f5d55a87cc84cebcae0f636b3' 
  AND token = '1wwH6Gfx2tbrtQhuK9AnZJcOwWkPtNsimmJ0nrOAu1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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