SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '617a8654cb6138875f06806d00513e6816125047038fdaa7316248c480565758' 
  AND token = 'RbBcBrudfLLlX1lMSjHzTnLaPgx3j6pxbtpHjfdB9xM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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