SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5e840d9fcc0ba8363d1adf86c851739e2ed1083c48fa85186f835c294f61bc48' 
  AND token = 'SgdJswApTfDfXVHN2g82i6tM4kCfCJEX0lXTYs6PfTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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