SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad4bf058312459c848b3a4d6358722f713387cbd53b9d097e04a22baeed512e0' 
  AND token = 'CIYvv0O73n+5CUFkIFOjiZm4aWDsZ1ihTQstH5Eilts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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