SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40610441c57b8361d9dda7b07980ed25290385b6b620c863fa6e33cf66b1b1f9' 
  AND token = 'ZAu2D/mu97gom4Sa0t9GKJ8iADUlK9uzaPlNBVTzvew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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