SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '214ff35e820175ed62a4dd174976d5ec90544d3675495f6b3af23e5f068aa31d' 
  AND token = 'IcMSPv6g6IlH73DWM22ZZlDmONBUnIU9qNRIASNP/4Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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