SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00fe6fec90b0afb0d6d01fccde2327ea9fd361a7881149afd962059bfc051b33' 
  AND token = 'tYsQUrbTXNfmtEiBL7/yX9LqyuFoT2tYNbEWpLaaa00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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