SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3935499f2e371fa53ebf66f04a19ba358947444fb2e5b6c61e73bc4900d9f39' 
  AND token = 'z7LATuWbdljKuVoPhKCh/2Id0aufMsHKUBcsv9RISYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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