SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5664f34678f61bf54967cc732587eb746a4169d0938f284b628b926a3d63118' 
  AND token = 'p5DLobfNB6joQowV5ZDABPqj6gjTutCcFn5SeGPFFGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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