SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57d5238564849d08a5de62c638f9e573219644cbbcadafe07f9f3fb776d02694' 
  AND token = '7H+wSmzlxsKrbk+oZiDm7Q4+dnAxqDRsQLJ+VGppqGs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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