SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5cf3f93620a8a6e5de8100136bda1bad9833a5c44d9e8c169726e77f803626c2' 
  AND token = 'HGbXZiJl3doLidZaLrK+IDWOcR3D6nov929coepBFbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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