SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6557d97ce21f455a96f0cd3aeac46fa9a213fc02e5cf8c252552999afc26a945' 
  AND token = 'Jh5dSdWRa5HSFP7gPXdXGdVUs0px0FDBsh1Dc6cTjVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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