SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b2bcbd444d13327d29ef0972d58ad298640da4a539aff614b5702715d2c3751' 
  AND token = 'TIFiF7F2Q3p+PkYgK8bWrKQ2qN8mBbkM+ZPrTgfZIxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}