SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d41810add54a55b3e8b6862d86aae9d8d0b3d3d124d666cb8cd6da98eed9338' 
  AND token = 'gSBiyqOoateXs0Uv5FJzyBQGLHpLRTN5voSltu5OncY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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