SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4202f40cea327b61fffe05e37a4835a760ac200b8dfdcb3039366cdc167092d' 
  AND token = 'PXBWe9GXteGb7qBDbUXdSVxCwHAzf0BB5n3odFlA7YM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}