SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b6479616a31a621b7f87a7fbb26c54ece54ef65574fb4cda3c59f18b65cd84d' 
  AND token = 'uK/MVW4kvqpU0j5h2xyLNGTUrXTCH/3kEtTor/+Kges=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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