SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23024a8a1ab831d91d365358292ad7aee9619150430affb018044d7c14245187' 
  AND token = 'LP/kSfXRsXbmtrkhWsIjEYpXGLCAIqleAdry93jzQKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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