SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddfd05b1643a97a85aef3eb5f8f48785ff9fe03093ed62463116baf83b0e147d' 
  AND token = 'LNjGNqlTKaQWYglMDHv4v3eLjDxleQSmYrQZ0m3NyDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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