SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5ac163818ce805ae50d0aad5f2f48ad3757223132df388d0e28b1c442b9a0151' 
  AND token = 'YB2g9SmLITNctWwxDFcC6PYXurBXci7UnWHTUSw3D3g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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