SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '42b7e15d581661a18fb2217410af259748e6a841b4bf6ec81ddd3cf850f55c90' 
  AND token = 'O4dIZQ/4fOLHgDW4OweLDMtXueIoflZ0m22k39vszuk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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