SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '62f9133170c679499a3d6a7aa6e33be2ebfd5ab6445e59800848da31d82ddd54' 
  AND token = 'tTg/4eablFb5r27isMw1SZ9TOXFKzdec4+akwzRr0/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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