SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9b08be8df068bd098d89bcf9b6a6eddb85842b6ab566fcbf6d0d571b2869862' 
  AND token = 'rc+OyEkAnTmoBPWjJIaESrqvUHPX8plgZRfOuQ1HFnM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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