SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56ac3dde1e874ee6860a02b81024f7119685f37990d0f56f12d7eef0a018e75c' 
  AND token = '8wIwk9Ns9KEuwQ1+JsDwOeNKPYYcNSo25A0w7dxZM98=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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