SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0a48fb5a8b75ca56e958aafa7907aa6874724e13d3d15f92d8c78358f3cf1b02' 
  AND token = 'IjmmFISh9NjDxzCVvkwRPDssJEPwsohViz/gkZczlv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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