SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db22be485bdc0c905df9b9fdfb314ea23a869506e267ac533f9b05e67746dbc8' 
  AND token = 'EZt6lFAvjsKwOuFKKlRyn8JzJewQXWFGSAR5vY72Avc=' 
  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"
    }
  }
}