SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a96a714bfb22d54cd42ed75af758b990844ac56d3e88c48e1d1196718af5ab83' 
  AND token = 'WWsO611g+PFOow330pLMLWDpvhPgtLXr2svP+wSYGuc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00062

JSON explain

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