SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66d4fdaa98b460340781be4e753fac3b6f2b22230e58c1e6a8b785b34bf2d881' 
  AND token = 'PlD1f8Y5FwEzE1X9VYLmhh1ZNYJOJC4Hkx88AYYVPzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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