SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f2a39b523c185c64465c9c8e36fea646654ba7a3a1f46686844a3f9dd1dbc32' 
  AND token = 'v8tp+vp/tuHzxscvLBubkYkXzk2maDx/O3IXSTfZf64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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