SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06c67e5a0fb5b9bd9d3519375397f6267f9febbc2f865eee4325bf649ca4a9dc' 
  AND token = 'kKlUJhVNxYBBx49InNWc4a+eVq7Us0K/WT8zKqsDBpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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